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Full text of "Concealing-coloration in the animal kingdom; an exposition of the laws of disguise through color and pattern: being a summary of Abbott H. Thayer's discoveries"



CONICEALING 



IN THE 

ANIMAL 
KINGDOM 



THAYER 



Property' of 
Whitney Studio Club 



LABORATORY 

OF ORNITHOLOGY 

LIBRARY 




CORNELL UNIVERSITY LIBRARY 




^: 



^^ 



Cornell University 
Library 



The original of this book is in 
the Cornell University Library. 

There are no known copyright restrictions in 
the United States on the use of the text. 



http://www.archive.org/details/cu31924022546406 



LABORATORY OF ORNIT HOLOGY 
CORNELL UNIVERSITlg ' ' ^ 
ITHACA, NEW YORK ' 



CONCEALING-COLORATION 

IN THE 

ANIMAL KINGDOM 



/ iu w/ t/ l/yt^O'UiLa Pcp tte^ TT 



EXPLANATION OF PI^TE I 



PEACOCK IN THE WOODS. 

painted by Abbott H. Thayer, assisted by Richard S. Meryman 



.The Peacock's splendor is the eflfect of a marvellous combination of 'obliterative' designs, 
in forest-colors and patterns. From the golden-green of the forest's sunlight, through all its 
tints of violet-glossed leaves in shadow, and its copipery glimpses of sunlit bark or earth, all 
imaginable forest-tones are to be found in this bird's costume; and they 'melt' him into the 
scene to a degree past all human analysis. 

Up in the trees, seen from below, his neck is at its bluest, and when sunlit, perfectly 
represents blu6 sky seen through the leaves. Looked down on, in the bottom shades of the 
-jungle, it has rich green sheens which 'melt' it into the surrounding foliage. His back, in 
all lights, represents golden-green foliagfe, and his wings picture tree-bark, rockj-etc., in 
sunlight and in shadow. His green-blue head is equipped with a crest which greatly helps 
it against revealing its contour when it moves. Accompanying its every motion, this crest 
is, as it were, a bit of background moving with it. The bare, white cheek-patch, on the 
other hand, 'cuts a hole,' like a Ughted foliage-vista, in the bird's face. The tail, when 
spread— 'or even when shut — 'ttungles' in a thousand ways with its jvUigle surroundingSi, The 
ocelli, guaranteed by their forest-scenery colors to vanish into the baclcground at a eb^ort 
distance, have one peculiarly fantastic use. Smallest and dimmest near the body, and growing 
bigger and Irighter in even progression toward the circumference of the tail, they inevitably 
lead the eye away from the bird, till it finds itself straying amid the foliage beyond the taD's 
evanescent border. 

The spread tail looks also very much like. a shrub bearing some kind of fruit or flower. 
Its coppery ground-color (in^ front view.) represents perfectly that of the bare ground and 
tree-trunks seen between the leaves. The very positiveness of the design in such details as 
an ocellus, works to conceal the wearer, on the principle explained in the Introduction by 
the quotation from Stevenson. The forest is so full of highly individualized vegetable forms, 
and of many-colored spots and streaks made by their confused outlines, that the predator's 
eye, watching mainly for moitow, doubtless gives but slight attention to any of them, or to 
anything that looks like one oj them. In addition to all this, every changed point of view on 
the beholder's part makes all the bird's details assvune new colors arid new correlations to 
each other and to the scene. — A. H. T. 



CONCEALING-COLORATION 

IN THE 

ANIMAL KINGDOM "fSrS.SLS?™''^ 



CORNELL UNIVERSITX 
ITHACA, NEff YORK r 



An Exposition of the Laws of Disguise 

Through Color and Pattern: 

Being a Summary of 

ABBOTT H. THAYER'S 
DISCOVERIES 



Bt 
GERALD H. THAYER 



WITH AH INTRODUCTORY ESSAY BY 
A. H. THAYER 



ILLUSTRATED BY 

ABBOTT H. THAYER GERALD H. THAYER 

RICHARD S. MERYMAN AND OTHERS 

AND WITH PHOTOGRAPHS 



NEW YORK 

THE MACMILLAN CO. 



1909 



T37 



3^1tOb 



Copyright, 1909, by Gerald H. Thayer 



ALL RIGHTS RESERVED 



THE TROW PRESS, NEW YORK 

LITHOGRAPHS AND HALF-TONES BY 
A. HOEN & CO., BALTIMORE 



PREFACE 

THE first publication of Abbott H. Thayer's discovery of "The law which 
underlies Protective Coloration" was in the American journal of 
ornithology, The Auk, in April, 1896. This was followed in the next issue 
of the same magazine by a supplementary article, "Further remarks 
on the law which underlies Protective Coloration." The two essays were 
illustrated by diagrams, and photographs, chiefly of dead birds. They were 
republished together by the Smithsonian Institution in its "Yearbook" for 
1898. A condensed revision of their text, with an introduction by Prof. 
Edward B. Poultori, was published in the English magazine. Nature, in 1902. 
Mr. Thayer has also given practical demonstrations of his discovery before 
various congresses of naturalists, both in the United States and in Europe, 
and has placed models illustrating it in several European museums (Oxford, 
Cambridge, and South Kensington, England, and Florence, Italy). Thus 
this newly discovered basal principle of Protective Coloration has been brought 
to the attention of most of the world's best naturalists, and the bare rudiments 
of the matter have become to some extent current knowledge among them,^ — 
though comparatively few of them have yet given proof that they perceive 
how completely this and certain parallel subsequent disclosures have revo- 
lutionized the study of Protective Coloration, and supplanted former theories. 
In the last few years, however, this discovery has been rapidly gaining recog- 
nition, and mention has been made of it in many writings on Natural His- 
tory, both popular and scientific, especially in England. Yet the subject is 
still very far from receiving its destined full and imiversal appreciation by 
nature students in general, and much of the current writing about the colors 
of animals is worse than useless, inasmuch as it works for the retention of 
antiquated delusions. Indeed, although the study of Protective Coloration 

vii 



is now generally acknowledged to be one of the most important branches of 
zoological science, there still exists among the otherwise well informed a 
complete ignorance and misconception of the main laws on which Pro- 
tective Coloration is based. 

The present book has been constructed for two main purposes: First, to 
lay before the comparatively few naturalists and others who have duly appre- 
ciated the original articles on the subject, the results of my father's further 
researches, with examples of the working of the newly revealed laws in many 
branches of the animal kingdom; and second, to present the matter, both in 
its simplest terms and variously elaborated, to a wider circle of readers. We 
hope thus to clear the way to a more general understanding and more intelli- 
gent study of the relations between animals' costumes and their environments. 
As the book stands, although it has a far wider scope than the previously 
published articles, it must be considered merely a fragmentary introduction 
to the huge and fascinating subject of Protective Coloration. Fundamental 
principles are defined, and many examples are given, both by illustrations 
and in the text, of the workings of these principles on actual animals; but 
nothing like an exhaustive examination of the species of any branch of zoology 
has been attempted. 

For the most part, we do not draw hypothetical conclusions from facts; 
but we reveal certain beautiful facts hitherto unknown; we disclose and ex- 
plain the remarkable power of several naturally applied laws of optical illu- 
sion — ^as these applications stand, by whatever causes produced, and as all 
may see them. That is, we show and analyze the concealing- power of the 
colors of animals as they exist to-day. 

The illustrations are of particular importance, inasmuch as they include 
what we believe to be the first scientific paintings ever published of animals 
lighted as they actually are in Nature. This will be explained in detail later 
on. The colored pictures have been painted either from mounted specimens, 
as in the cases of the Grouse, the Wood Duck, and the Peacocks, or from 
live captives, as in the cases of the Snake and all the Caterpillars. The pic- 

viii 



ture of the Grouse is a faithful copy of a specimen in a house-lighting arti- 
ficially arranged to correspond to that which the live bird in the forest would 
normally have; while the background was painted from photographs and 
outdoor color sketches. The Snake is the joint production of A. H. Thayer, 
Rockwell Kent, and G. H. Thayer. Three of the caterpillar pictures are 
contributed by Louis A. Fuertes. The Bird of Paradise sketch is largely 
the work of Mrs. A, H. Thayer; likewise most of the background in the rab- 
bit picture, the diagrams of 'ruptive' coloration, and two or three black-and- 
white diagrammatic drawings; besides a good deal of contributive work here 
and there on other paintings; and an immense amount of miscellaneous labor, 
invaluable advice and criticism, at almost every point. 

The various photographs of live birds and mammals which appear in the 
book have been gleaned from periodicals, or secured by special advertising. 
We are particularly indebted for valuable pictures to the late Mr. Evan Lewis, 
of Idaho Springs, Colo.; to Mr. Edward R. Warren, of Colorado Springs; to 
Prof. F. A. Herrick, to Dr. T. S. Roberts, to Mr. George C. Embody, to Prof. 
F. A. Lucas, and to Mr. C. Wm. Beebe; also to Mr. R. L. Ditmars, Curator of 
Reptiles at the Bronx Zoological Park, New York, for the loan of a live Copper- 
head snake, and other favors. 



IX 



TABLE OF CONTENTS 

PACE 

Introduction: by Abbott H. Thayer. An Essay on the Psychological and other basic 

Principles of the Subject 3 

CHAPTER I 

Outline of the book's scope. "The Law which underlies Protective Coloration" introduced 

and analyzed. Poulton cited 13 

CHAPTER n 
Definition of terms. Obliterative Shading, pure and simple 24 

CHAPTER III 
First principles of the use of markings with obliterative shading. 'Picture-patterns' ... 30 

CHAPTER IV 
Picture-patterns, with obliterative shading, on birds. American Woodcock, and Snipe . . 33 

CHAPTER V 

Picture-patterns on obliteratively-shaded birds, continued. Terrestrial Goatsuckers (Whip-poor- 
wills, etc.) 35 

CHAPTER VI 

Picture-patterns on counter-shaded birds, continued. Forest Grouse, Owls, European Wood- 
cock 38 

CHAPTER VII 

Picture-patterns on counter-shaded birds, continued. Grass-patterns, heather-patterns. Spar- 
rows, Waders, Ptarmigan, etc 44 

CHAPTER VIII 

Picture-patterns on counter-shaded birds, continued. Scansorial (Climbing) birds. Creepers, 

Wrynecks, Woodpeckers, etc 40 

xi 



CHAPTER IX 

PACE 

Picture-patterns on counter-shaded birds, continued. Shore-birds — Sandpipers, Plovers, etc. 

Beech-sand-, pebble- and grass-picturing patterns. Generalizations and comparisons . 52 

CHAPTER X 

Picture-patterns on counter-shaded birds, continued. Reed-pattems, etc., of Bitterns. Other 

Herons: water-colors and patterns 56 

CHAPTER XI 

Background-picturing on counter-shaded birds, continued. Marsh-birds: Water-birds (Galli- 
nules, Rails, Ducks, etc.): detailed analysis of the Wood Duck's consummate picture- 
patterns 59 

CHAPTER XII 

Background-picturing on counter-shaded birds, continued. Birds of the ocean. Sky- and 

water-matching costumes. Gulls, Terns, Gannets, etc. 72 

CHAPTER XIII 

Birds, etc. The inherent 'obliterative' power of markings. 'Ruptive' and 'secant' patterns, 

etc 77 

CHAPTER XIV 

Birds, etc. Special functions of markings. Circle-banded flight-feathers of Hawks and Owls. 

Eye-masking patterns: eye-blazoning (?) patterns. The coloration of nestling birds . 80 

CHAPTER XV 

Birds. Masking of bill and feet for offensive purposes. The "pantaloons" of Hawks and Owls. 
Gaudy bills and feet of Water-birds: red and yellow on many water-animals: Belt cited. 
Jacanas, Anhingas, Herons, etc. 84 

CHAPTER XVI 

Birds, etc. The manifold obliterative power of iridescence. Changeable colors in general: 
their part in water-picturing costumes, etc.; (Peacock), Jacamar, the "speculum" of 
Ducks, 'jewel-spots,' etc - 87 

CHAPTER XVII 

Birds, etc. Appendages, and their part in 'obliteration': Resplendent Trogon: Pheasants and 
their long, transversely-banded tails: consummate obliterative equipment of the Birds-of- 
Paradise . 95 

CHAPTER XVIII 

Birds: miscellany. "Mimicry" (vs. 'obliteration'). The gorgeous head-gear of Humming- 
birds not mimetic; its obliterative functions, etc. Sexual differences of costume . . 100 

xii 



CHAPTER XIX 

PAGE 

Birds, concluded. The birds of tropical forests : brown ground-birds : gaudy perchers on tree-tops : 
tree-top skulkers, etc.: Parrots and parrot-tails: Toucans: ruptive patterns, iridescence, 
appendages: extreme color-contrasts: juxtaposition of complementary colors: green light: 
Trogons and Tanagers: Chapman cited; etc. Winter birds of the snowy North: Blue 
Jays, Magpies, Goshawks, Titmice, Woodpeckers, cone-birds, etc. White in birds' 
costumes. Generalizations and comparisons ■ - - 107 

CHAPTER XX 

Mammals. A running survey of the coloration of mammals, from bats to whales. Full oblitera- 

tive shading almost universal among them. Exceptions considered .... 119 

CHAPTER XXI 

Mammals, continued. The markings of coimter-shaded mammals: the main types of their 
obliterative picture-patterns. Leopards, Giraffes, Zebras, Tigers, Antelopes; Hares, 
Ground Squirrels, etc., etc . 132 

CHAPTER XXII 

Mammals, concluded, etc. Patterns of mammals that are not counter-shaded. Sky-matching 
patterns of mammals. 'Sky-pictures' on the backs and fronts of Skunks, Zorils, Teledus, 
Ratels, Ant-eaters, etc. White snow-animals: black markings on white: Ptarmigans, 
Weasels, etc. Sky-matching white rumps and tails of many fleet ruminants and rodents 
(Deer, Antelopes, Hares, etc.). Flamingoes, Spoonbills, etc., and morning and evening 
skies. Other examples of sky-picturing on birds, compared with mammalian sky-picturing. 
'Dazzling-marks,' fixed and eclipsable; and other special phases of pattern-use. Merriam 
cited. Generalizations and comparisons . . . 147 

CHAPTER XXIII 

Fishes. Counter-shading universal among them: exceptions: deep-sea fishes: cave-fishes. The 
two great divisions of daylight fishes: free-swimmers and the haunters 0} submerged land. 
Flat-fishes: Crabs: Rock-fishes. 'Paradise' fishes of the tropics. "Mimicry" among 
fishes. "Chameleonism" in fishes. Fresh-water fishes. Trout and "trout-spots." 
and Fishes seals. Summary . . . . . j6o 

CHAPTER XXIV 

Reptiles and Amphibians. Counter-shading universal among them. Tree-snakes and -Lizards. 
Grass-snakes. Unmarked, striped, and banded snakes. Rattlers, Copperheads, Puff 
Adders, etc. Markings of lizards, and chameleonism. "Mimicry" (?) among snakes 
and lizards. Crocodilians. Tortoises and Turtles. Frogs and Toads. Elaborate 
obliterative coloration— counter-shading and picture-patterns— of certain frogs, toads, and 

tree-toads. "Mimicry" among them. Newts, Salamanders, etc lya 

xiii 



CHAPTER XXV 

PAGE 

Caterpillars. Manifold variations of form and habit: manifold variety of devices for conceal- 
ment. Predominance of counter-shading: "Mimicry" : 'Obliteration ' and "Mimicry" com- 
bined. Inchworms. Luna, Polephemus, Sphinxes. Leaf-edge caterpillars (on maple, 
birch, beech, oak, etc.). 'Mirror-backed' caterpillar. Plumed dead-leaf caterpillar. 
Dead-leaf-mimicking sphinx. Pine-tuft sphinx. Lappet caterpillar. Concluding re- 
marks iSj 

CHAPTER XXVI 

A glance at Insects other than Lepidoptera (Grasshoppers, Crickets, Beetles, Bees, Wasps, Flies, 
Dragon-flies, etc.), and at Spiders. Obliterative shading and picture-patterns on terrestrial 
locusts, etc. 'Dazzling'-colors. 'Obliteration' and leaf-mimicry among grasshoppers. Ob- 
scure coloration of crickets. Iridescence, 'ruptive' patterns, etc., of beetles. Counter- 
shading and bark-patterns of cicadas. Plant-lice. Water-insects. Obliterative patterns 
of wasps and bees: iridescence. Dim colors and obliterative markings of the Diptera 
(Flies, gnats, etc.). Ants.. Beautiful obliterative costumes of the dragon-flies: (counter- 
shading, vivid colors, iridescence, picture-patterns). 'Mimetic' dragon-flies. Larval and 
pupal insects 198 

CHAPTER XXVII 

Butterflies and Moths. Their costumes all concealing, from the gaudiest to the dullest. Changes • 
in environments: tropical forests. Earlier estimates of the subject: our limitations. Essay 
in English Entomological Society's "Transactions" cited. "Mimicry, Common Warning 
Colors, and Sexual Selection.'' The comparatively small part played by counter-shading. 
Immense variety of background-pictures. 'Sedentary' and 'aerial' butterflies. Kallima 
inachis. Other types of leaf -mimicry. Heliconius melpomene: its flight-pattern: its re- 
markable roosting-habits. Dainty leaf- and flower-pictures; Metamorpha, Euchloe. 
Bark-butterflies: wing-folders; Grapta, Vanessa, Calligo, etc. Ground-butterflies: of the 
fields: of the forest. Wing-waving. 'Intermediates.' Shadow-color: sunlit-foliage color. 
PapilionidcB. Sun-flecks: sun-streaks: Heliconius chariionia: shimmering foliage. ' Rup- 
tive ' flight-patterns. Hummingbird-Papilios. Heliconius melpomene z%am. "Batesian 
and MuUerian Mimicry groups." Clear-winged butterflies: Bates quoted. Iridescence: 
major: minor, il/or^/io^: of the tree-tops: of the forest: 'dazzling' effect. Obliterative 
patterns analysed. 'Ruptive ' patterns again. Flower-like-ness. The ocellus. Owl (?) 
butterflies. Major and minor ocelli. Appendages. Enormous size of butterflies' 
wings, relative to their weight: comparison with bees and birds. 'Obliteration' of 
butterflies' bodies. Erratic flight. Moths. Urania: 'target-marks.' 'Flat-folding.' 
Bright hind wings and masking fore-wings. Marvelously detailed picture-patterns. Near 
backgrounds. Flat-folding butterflies. Grass-moths (like ptarmigans and grass-frogs). 
'Obliteration' and "mimicry." Perpendicularly- and cylindrically-folding moths. Extreme 
types of bark-picturing, and peculiar habits accompanying some of them. Dead-leaf 
moths. £)Ma/i/y of moths' and butterflies' patterns. Nature's picture-painting again: con- 
cluding remarks 212 

xiv 



LIST OF ILLUSTRATIONS 

COLORED PLATES 



FLATE 



rACING 
rAGE 



I. — Peacock amid foliage Frontispiece 

II. — Male RuSed Grouse in the forest 38 

III.— Two sketches of male Wood Ducks, in the water 59 

IV.— Male Wood Ducks 7° 

V. — Colored diagram illustrating the use of 'ruptive' coloration 77 

VI. — Blue Jays against snow, and Birds-of-Paradise in the tropical forest .... 107 

VII. — Cottontail Rabbit among ferns and moss and grasses 119 

VIII. — Roseate Spoonbills, and the skies they picture 147 

IX.— Roseate Spoonbill, Red Flamingoes, and twilight sky 156 

X. — Flamingoes, at dawn or sunset, and the skies they picture 156 

XI. — Copperhead Snake on dead leaves 172 

XII. — Caterpillars (Luna and green sphinx) . . 183 

XIII.— Caterpillars (of beech-, birch- and elm-leaf-edges) 188 

XIV. — Caterpillars (of beech- and oak-leaf-edges, etc.) 192 

XV.— Caterpillars. (Mirror-back larva, dead-leaf sphinx, frond-bearing larva) . . .194 
XVI.— Caterpillar, and spider. (Pine-tuft sphinx, porcelain-white spider) . . . .196 



BLACK-AND-WHITE FIGURES 
(Photographs from Nature, etc., and diagrams.) 

Diagram in the text, 3 figs., Chap. I 14 



rACIHG 
PAGE 



FIGURE 

I. — Models illustrating the use of counter-shading. Photograph 24 

2. — Model illustrating the use of counter-shading. Photograph 24 

3. — Models illustrating the use of counter-shading. Photograph 24 

4. — Models illustrating the use of coimter-shading. Photograph .... 24 

5. — Models illustrating the use of counter-shading. Photograph 24 

6. — Plymouth Rock hen conspicuous against Plymouth Rock hen skins. Photograph . . 26 

XV 



PACING 

FICnSE PAGE 

7. — White fowl against white cloth. Photograph 26 

8. — White-tailed Ptarmigan in winter plumage, on snow. Photograph 26 

9. — White-tailed Ptarmigan in winter plumage, off snow. Photograph 26 

10. — White-tailed Ptarmigan in winter plumage, on snow, but strongly shadowed. Photograph 26 

J 2. ^Photographs of the flat skins of birds and mammals 28 

I3-— J 

14— " 

15. — 

, ("Bird-models illustrating the first principles of pattern-use. Photographs ... 30 

17.— J 

18. — Pattern perspective. Diagram 32 

19. — Pattern perspective. Diagram 32 

20. — "I 

[-Nesting American Woodcock. Photographs 32 

22. — Nesting American Woodcock. Photograph 33 

23. — Dead Woodcock, with the counter-shading painted out. Photograph . . . . ^^ 

24. — Dead Woodcock on its side, back -view and front-view. Photographs .... 33 

25. — Nesting Wilson's Snipe. Photograph 34 

26. — Jack Snipe feeding. Photograph 34 

27. — Nesting Whip-poor-will. Photograph 35 

28. — Nesting Whip-poor-will. Photograph 35 

29. — Nesting Nighthawk. Photograph 36 

30; — Nesting Nighthawk. Photograph 36 

31. — Ruffed Grouse walking. Photograph 37 

32. — Nesting Ruffed Grouse. Photograph 37 

33. — Nesting Ruffed Grouse. Photograph 40 

34. — Dead Ruffed Grouse on its side, back -view. Photograph 40 

35. — Dead Ruffed Grouse on its side, front-view. Photograph 40 

36. — Bit of Great Homed Owl's wing, and bit of pine forest. Photographs . . - 41 

37. — Stuffed Long-eared Owl in pine-woods. Photograph . 42 

38. — Stuffed Long-eared Owl among evergreen twigs. Photograph 42 

39. — ^White-tailed Ptarmigan in transitional plumage. Photograph 44 

40. — White-tailed Ptarmigan in summer plumage, nesting. Photograph 44 

41. — ^White-tailed Ptarmigan in summer plumage, nesting. Photograph . . . . 44 

42. — ^White-tailed Ptarmigan in summer plumage, with chick, among rocks. Photograph . 44 

xvi 



PIGDRE 

43- 
44- 
45- 
46.- 

47-- 
48.- 

49- 
50.- 
SI-- 
52- 
S3-- 
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S5-- 
■56.- 
57- 
S8.- 
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65-- 
66.—: 
67. 
68.—: 

69. 
70. 
71. 

72. 

73-— • 

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75- 

76.- 

77.—. 

78,- 



■Sage Grouse. Photograph 

■Scotch Grouse (Ptarmigan), nesting. Photograph 
■Scotch Grouse (Ptarmigan), nesting. Photograph 
■Young Meadowlarks in the nest. Photograph 
■Female Eider Duck on her nest. Photograph 
■Young Short-eared Owls in the nest. Photograph 
■Yellow Wagtail amid grasses. Photograph . 
■Male Bobwhite, nesting. Photograph 
■Golden Plover, with chick, in grass. Photograph 
■Nesting "Upland Plover." Photograph 
■Nesting American Bittern. Photograph . 
■Nesting Virginia Rail. Photograph .... 
■Nesting Wilson's Tern. Photograph 



Artificial monochrome butterflies, against light and dark. Photograph 



■Chestnut-sided Warbler feeding young. Photograph . . , 
■Chestnut-sided Warbler (and Catbird). Photograph . 
Blue Jays amid foliage. Photograph 
Chickadee at nest -hole. Photograph 
■Oyster-catcher on rocks. Photograph 

■Guillemots on rocks. Photograph 

Stuffed Goshawk against pine-tops. Photograph 
Tip of Goshawk's wing against pine branches. Photograph 
Stuffed Goshawk on its back on the forest floor. Photograph 
Baby Golden Plover. Photograph . 
Ringed Plover, at its nest. Photograph . 
Lapwing on its nest. Photograph 
■Killdeer Plover on its nest. Photograph 
•Killdeer Plover at its nest. Photograph 
Baby Killdeer Plover, crouching. Photograph 
Nighthawk chick, on the ground. Photograph 
■Nighthawk chick, on the ground. Photograph 
■Baby Common Gulls. Photograph 
Baby Curlew. Photograph 
Baby Crested Grebes. Photograph . 
■Baby Red-breasted Mergansers. Photograph 

xvii 



FACING 
PAGE 

44 

46 

46 

46 

46 

46 

48 

48 

48 

48 

58 

58 
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78 

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78 

78 

78 

78 

78 

80 

80. 

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82 



FIGURE 

79-- 
80.- 
81- 
82.- 

83- 
84.- 

8S-- 
86.- 

87- 
88.- 
89.- 
90.- 
91.- 
92.- 

93-- 
94.- 

9S-- 
96.- 

97-- 

98.- 

99.- 

loo.- 

lOI.- 
102.- 
103.- 
104.- 
105.- 
106.- 
107.- 
108.- 
109.- 
110.- 

iir.- 
112.- 
"3- 



Glinting pool amid grasses. Sketch 82 

Baby Homed Grebes on their nest. Photograph 82 

[• Baby Woodcock. Photographs 82 



-Hairy Woodpecker in winter woods. Photograph (of stuffed bird) and sketch, combined 
-Cottontail Rabbit crouching. Photograph 

-Domestic Hare. Photograph 

-Domestic Hare laid on its back. Photograph 

-Captive Jaguar. Photograph and sketch (of background) combined 

-Wild Zebras at a drinking-place. Flashlight photograph 

-Wild Zebras. Flashlight photograph 

-Cardboard zebra, No. i. Photograph, retouched 

-Cardboard zebra, No. 2. Photograph, retouched 

-Cardboard zebra. No. 3. Photograph, retouched 

-Chipmunk among dead leaves. Photograph . 

-Mbega Monkey. Photograph .... 

-Common Skunk against sky and bushes. Photograph (stuffed skin) 

-Common Skunk against sky and bushes, side-view. Photograph (stuffed skin) 

-Common Skunk against sky and bushes, nearer view. Photograph (stuffed skin) 

-Common Skunk against dark. Photograph (stuffed skin) 

-Prairie Skunk against the sky-line. Photograph from stuffed skin 

-Prairie -Skunk against dark. Photograph from a stuffed skin 

-Spilogale against sky-line. Photograph from stuffed skin . 

-Spilogale against the ground. Photograph from stuffed skin 

-A compound picture, of Skunks and Hares. Photographs (and drawing) 

-Diagram illustrating the use of 'dazzling'-marks. Photographic 

-Diagram illustrating the use of 'dazzling'-marks. Photographic 

-Diagram illustrating the use of 'dazzling'-marks. Photographic 

-Stuffed Prong-buck, rear-view, against sky. Photograph 

-Stuffed Prong-buck, rear-view, against ground. Photograph 

-Stuffed Prong-buck, half side-view, silhouetting against sky. Photograph 

-Prong-buck as in Fig. 109, but photograph shaded to suggest night-effect. Photograph, 

retouched . . . . 

-Deer or Antelope silhouetted against night sky. Sketch ... 

-Dead Hare, rear-view, against sky. Photograph 

-Dead Hare against ground. Photograph 

xviii 



114 
128 
128 
128 
132 

13s 
136 

138 
138 
138 
138 

146 

148 
148 
148 
148 
148 
148 
150 
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150 
152 
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154 

154 

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154 



nODIE PACE 

114.— White card against sky. Photograph iS4 

115. — White card against ground. Photograph 154 

116. — Imitation Egret, without plumes. Photograph . . 156 

117. — Imitation Egret, with plumes, against dark. Photograph 156 

118. — Imitation Egret with plumes, against white. Photograph 156 

119. — Diagram illustrating the effect of certain patterns. Drawing ... . 159 

120. — Fifty little pictures, mainly photographic, of real holes, and of counterfeit holes in animals' 

patterns 159 

121. — Green Snake, right-side-up. Photograph 174 

122. — Green Snake, inverted. Photograph . . 174 

123. — Rattlesnake among stones. Photograph and drawing 174 

124. — Brown Lizard on apple-tree bark. Photograph 180 

125- — ) 

> Brown Wood Frog among dead leaves. Photographs 180 

120. — ) 

127. — Common Garden Spider on its web. Photograph 180 

128. — Orange-tip Butterflies on cow-parsley. Photograph 216 

129. — Butterflies on vegetation. Photograph 216 

130. — Light butterfly with shadow-colored fore-wing borders. Photograph . . . 216 

131. — Small Tortoise-shell Butterfly on pebbles. Photograph 216 

J32. — Ocellus on a butterfly-model. Photograph . 230 

133. — Moths, Butterfly, and Pheasant's tail, on dead leaves, etc. Photograph .... 230 

134. — ^Two Grass-moths, on grass. Photograph . 235 

135. — Tiger-moth on sprig of Box. Photograph 235 

136. — Four Bark-moths, on Maple bark. Photograph 235 

137. — Two Bark-moths on Pitch Pine. Photograph 235 

138. — Three Bark-moths, on Gray Birch. Photograph 235 

139. — Pandorus Sphinx Moth on a White Birch tree. Photograph 237 

140. — Bits of sphinx-moth pattern and of bark-pattern intermingled. Photographic . . . 237 



XIX 



CONCEALING-COLORATION 

IN THE 

ANIMAL KINGDOM 



INTRODUCTION 

WHILE man has gone on wresting from Nature one deep-buried secret 
after another, the whole field of protective coloration has lain un- 
concealed, inviting recognition, resplendent with wonderful and beautiful 
phenomena. Yet of these he has remained uncognizant, or caught only 
fragmentary glimpses, piecing together the fragments with the aid of false 
hypotheses, which have presented such a spectacle of inconsistency as to 
bring the whole subject into widespread contempt. 

The entire matter has been in the hands of the wrong custodians. Apper- 
taining solely to animals, it has naturally been considered part of the zoolo- 
gists' province. But it properly belongs to the realm of pictorial art, and can 
be interpreted only by painters. For it deals wholly in optical illusion, and 
this is the very gist of a painter's life. He is born with a sense of it; and, 
from his cradle to his grave, his eyes, wherever they turn, are unceasingly at 
work on it, — and his pictures live by it. What wonder, then, if it was for him 
alone to discover that the very art he practices is at full — ^beyond the most 
delicate precision of human powers — on almost all animals? Fortunately, 
although this search, like all others, requires a specialist, the beautiful things 
discovered are appreciable by all men; and our book presents, not theories, 
but revelations, as palpable and indisputable as radium or X-rays. 

Naturalists have not understood the principles of objects' distinguishability. 
Let us first consider the part distinguishability plays in animals' lives. Sight, 
in the great majority of cases, is the sense by which at the last moment the 
quarry's fate is decided. Had the cougar, wolf, or fox no eyes, he would 
starve. Had the hare no sight, he could not teU when to abandon his 
squatting and spring away, or which way to dodge the murderous leap that 
would follow. Scent brings the predator along the trail or up-wind nearly to 
the game, but were this pursuer blind, he would seldom (except in 

3 



holes) * catch anything more active than a tortoise, as everyone knows who 
has watched a cat, dog, or ferret falteringly nosing out the whereabouts of a 
bit of flesh, or a setter pointing a bird. The dog commonly points the stream 
of scent that is passing his nose, without the slightest appearance of knowing 
where the bird is. In fact, for the purpose of knowing just where their game 
is, scent offers animals no immediate aid; and the same is true of sound. For 
scent and sound can go round corners, whereas sight operates solely in a 
straight line. Sight is also out of all proportion the swiftest; for while scent 
moves practically only at the air's rate, and sound only 1,121 feet a second, 
light, which means sight, travels 182,000 miles a second! This combined 
straightness and swiftness gives sight, and sight alone, the power to tell the 
predator exactly where his quarry now is, and the quarry where his enemy is. 
Thus, at these crucial moments in the lives of animals, when they are on the 
verge of catching or being caught, sight is commonly the indispensable sense. 
It is for these moments that their coloration is best adapted, and, when looked at 
from the point of view of enemy or prey, as the case may be, proves to he ' obliter- 
ative.' All experiment corroborates our supposition that human and animal eyes 
bear essentially similar relations to light vibrations. (And, in fact, almost all 
theories about the functions of animal's colors are based on this hypothesis.) 

All naturalists perceive the wonderful perfection of the twig mimicry by 
an inchworm, or of bark by a moth, or of a dead leaf by the Kallima butter- 
fly. It is now apparent that almost equally marvelous concealment-devices, 
in one shape or another, are general throughout the animal kingdom; the 
most gorgeous costumes being, in their own way, climaxes of ohliterative color- 
ation scarcely surpassed even by moths or inchworms. 

This discovery that patterns and utmost contrasts of color (not to speak 

of appendages) on animals make wholly for their 'obliteration,' is a fatal 

blow to the various theories that these patterns exist mainly as nuptial dress, 

warning colors, mimicry devices (i. e., mimicry of one species by another), 

etc., since these are all attempts to explain an entirely false conception that 

* In the case of the weasel family, this exception is doubtless a large one. 

4 



such patterns make their wearer conspicuous. So immeasurably great, in the 
case of most animals, must be the value of inconspicuousness, that such de- 
vices as achieve this to the utmost imaginable degree, upon almost every liv- 
ing creature, demand no further reason for being (although doubtless serving 
countless other minor purposes). 

The theory of Natural Selection is based on the belief that organisms are 
susceptible of modification limited only by the duration of the circumstances 
causing it, or by the attainment of ultimate perfect fitness to environment. 
Now, since the same circumstances would always be best met by the same 
characters in an organism, we are not surprised to find aU animals, of how- 
ever widely different orders, resembling each other in shape and color in evi- 
dent proportion to their degree of having the same habitat and habits. The 
whole class of mammals, dwelling mainly on the ground, have mainly ground 
color, and a form varying no more than their situations and habits. The 
same thing is equally true of thousands of species of birds, of fishes, reptiles 
and insects; even mammals, if they lead a fish's life, like the cetaceans, have 
the general shape and color of fishes. (A parallel case is that of humming- 
birds and hawk moths.) No fish of the open ocean is permitted by Nature 
to wear any essential color-distinction from his hundreds of neighbor species. 
He has, for aU we know, the same need of "warning colors," "banner marks," 
etc., as any land animal; but Nature vouchsafes him no pin-point of color be- 
yond that of the sky-lit deep-sea water. The same is true of the inhabitants 
of the aerial ocean spaces. Save for a good many small, bright-colored dec- 
orations, mainly of the beaks, worn by such species as breed where such col- 
ors abound. Nature allows them no colors which are not those of sea surfaces, 
clouds and sky, or of somber cliffs; or, for the diving ones, dim water-colors, 
more like those of the fishes themselves. In short, the so-called "nuptial 
colors," etc., are confined to situations where the same colors are to be found 
in the wearer's background, either at certain periods of his life, or all the time. 
Apparently, not one "mimicry" mark, nor one "warning color" or "banner 
mark," nor one of Gadow's light-and-shadow-begotten marks, nor any "sex- 

5 



ually selected" color, exists anywhere in the world where there is not every 
reason to believe it the very best conceivable device for the concealment of its 
wearer, either throughout the main part of this wearer's life, or under certain 
peculiarly important circumstances.* 

These deceptive patterns, painted by Nature on the exteriors of almost all 
animals, will prove to be an inexhaustible field for studying their psychology. 
Stevenson makes Alan Breck say "Them that cannae tell the truth, should 
be aye mindful to leave an honest, handy lee behind them. If folk dinnae 
ken what ye're doing, Davie, they're terrible taken up with it; but if they think 
they ken, they care nae mair for it than what I do for pease porridge." The 
psychological principle in this lies deep in Nature's artifices for concealing 
animals. Wherever, for instance, the animals are habitually to feed amidst 
brilliant vegetation, she is apt to give brilliant marks rather than simply equip- 
ping them to match the soberer interstices amidst the brilliant details. The 
principle is, evidently, that amidst a large number of similar striking objects, 
an imitation of these has the support of the credit of all the real ones. There are 
before the eye so many obviously real ones, that the mind refuses to take the 
trouble to suspect any. For a red mark on a bird, fish, or butterfly to pass 
itself off for a red flower among many red flowers is like Alan's telling the 
passer-by that his errand is such a familiar one as the search for a runaway 
horse; while, in such a situation, to try to escape notice by imitating a dusky 
place, may be as much more risky as for Alan to assert merely that he is not 
on a mysterious errand.f The so-called "nuptial" costumes of animals are 

* Plainly, most details of an animal's body serve many purposes; and whatever law develops 
the detail's main characterisiics,.doubt\ess causes it also to be modified to meet each minor use, in the 
degree of its relative importance. To illustrate with human experiences, the hunter's rifle, besides 
its main use, serves also at times the purpose of a balancing-pole, or even a club; and, carried over 
his shoulder as he goes away, it serves to show his family that there may be venison for dinner; yet 
its essential purpose is to kill that venison, — for this, nothing but a rifle would serve. In the same way 
animals' markings doubtless serve in various lesser degrees most of the purposes that have been 
attributed to them. 

t Another good analogy is the universal human propensity to trust circumstantial evidence too 
much; to believe any accused person guilty, because the sin he is accused of is a common one. 

6 



demonstrably an increase of such potency of obliterative coloration as belongs 
to all gorgeously varied costumes, and this at the very period when concealment 
is most needed. 

It is of great importance to understand that skill and strength are not all 
confined to predators. It is plain, upon any hypothesis whatever which rec- 
ognizes the existing fitness of all forms of life to their uses, that this fitness is 
presumably just as great in the quarry's case as in the hunter's. The fleet- 
ness and alertness of the hare are a good match for the stealth and power 
of the lynx, etc., and the consequent balance between predator and prey is 
doubtless known to the instincts of each animal. The lynx's obliterative col- 
oration just as much increases his dangerousness to the hare, as that of the 
hare adds to the lynx's difficulty in catching him. 

Although inconspicuousness is merely an approach to indistinguishability 
(of course this positive term refers only to occasional effects), yet the practical 
workings of the two are worth considering . separately. Indistinguishability 
enables predators to ambush their prey, and, on the other hand, it protects 
any quarry to the windward of which the predator may pass (if he is not trail- 
ing it). Mere inconspicuousness of the predator causes him to be less avoided 
by the animal he preys on, while for the prey it means a minimizing of the 
stimulus he gives to his enemy's rapacity. Also, at the ultimate moment 
both sides profit by showing as indistinctly as possible, so that the rapacious 
animal is harder to dodge, and the prey a fainter target to strike at. Sports- 
men, insect-catchers, and tennis players will understand this. Again, in a 
very large class of cases the question is not whether the hawk, for instance, 
can espy, or the fox, scent, his game, but whether there appear to him, at the 
moment, sufficient advantages on his side to stimulate him to an effort such 
as has far more often failed than succeeded. Also, a single instant of success- 
ful disguise suffices to protect an animal from a swiftly passing marauder, a 
hawk, for instance. In a rapacious animal's case there must be an eternally 
shifting balance between greed and inertia. Doubtless a sufficiently strong 
incentive — a very obvious chance — ^might rouse even the most gorged of 

7 



hawks to attempt another capture; while, on the other hand, one that was 
starving, or whose young were, would achieve marvels of daring and power. 
Watch an Accipiter sitting amidst the usual abounding bird life of summer 
woods. You will often look long for any sign that the smaU birds fear him, 
or that he threatens them. One evidence that this balance of circumstances 
is what keeps the two classes of animals so peaceful in their general demeanor 
toward each other is to be found in the alacrity with which predatory animals 
rush to investigate an imitation of a bird's or mouse's cries of distress. So, 
too, a pickerel, after long listlessly watching your bait, with the barest signs 
of interest, will often seize it the moment it gets foul of a lily pad and seems 
in difficulty. Other things being equal, animals that hunt by sight (i. e., do 
the whole thing by sight, as hawks do in distinction from most rapacious 
quadrupeds) would try for the most conspicuous prey, just as a sportsman is 
almost irresistibly drawn to shoot at the best mark in a flock of birds — so 
much so, that, if he be a beginner, he may let them all go by, after swinging 
his gun upon one after another of them, unable to keep to the one first se- 
lected, when another has become more conspicuous. 

Just as men who live amidst constant danger have powers of instantane- 
ous action unknown to farmers and shopkeepers, so the hare and the deer 
have acquired in their hard school similar alertness and speed. In terms of 
the theory of natural selection, the quarry has had just as many centuries to 
learn his part, as the predator to learn his. Evidently, the hawk's nerves know 
this so well that, instead of wasting energy, they, so to speak, 'take into their 
own hands' the business of being ever ready to hurl him like lightning on a 
disabled or preoccupied victim. 

Since we may assume that there is this closest balance between the respect- 
ive powers of predaceous animals and their game, it follows that, in the long 
run, smallest advantages will tell. And if they do tell, the same process, what- 
ever it be, that has adjusted moths to bark and made inchworms look exactly 
like twigs, must be everywhere at work, carrying each advantageous trait to 
similar perfection. 



In the days of swordsmanship, there was Httle difference between fine 
fencers, yet the best one would, by the most delicate shades of superiority, get 
his sword through his opponent's ribs in one fight after another till all men 
feared him. That such things are more than luck is well known to life- 
insurance companies and army recruiters. Why do they take no chances, 
but, instead, calculate averages, and reject each applicant whose defects exceed 
the limit, even in cases where this applicant has a great many chances of con- 
tinued health — ^where he may outlast sounder men? If war departments 
know that minute defects in individual soldiers will affect even a single cam- 
paign, how is it conceivable that, in the animal kingdom (if there be natural 
selection at all, or any corresponding principle), hundreds of thousands of 
years should leave any sifting unperfected, any slightest adaptation incom- 
plete? All characters, barely noticeable by us, but which are in the long run 
of more use than harm, must develop. 

This book demonstrates that the colors, patterns, and appendages of ani- 
mals are the most perfect imaginable effacers under the very circumstances wherein 
su^h effacement would most serve the wearer. For any particular animal to 
be seen looking conspicuous means no more than that he is not at those 
moments looked at under the circumstances for which his concealing-colors 
are effective; and man's persistent misconception that bold patterns, etc., 
make the wearer conspicuous, is based on a psychological principle. Let us 
imagine one hundred butterflies of the same species within range of a nat- 
uralist's sight, and ninety-nine of them concealed from him by the effect of 
their bold patterns, while the hundredth happens to be noticed by him, and, 
of course, identified by all its attributes, bold pattern and all. What impres- 
sion about the species has this naturalist gained through this experience? He 
carries away simply one more mental picture of a butterfly of this boldly 
patterned species, and mistakes its specific recognizability for intrinsic con- 
spicuousness. The ninety-nine successful disguises have made no impression 
at all. So he goes on, accumulating a conviction that the species is conspic- 
uous. He can tell you a long list of cases to prove it: — while the actual case 

9 



is, that for every one he saw there were as a rule scores, within range of his 
sight, concealed by the very patterns which he behaves to make the species 
conspicuous! I had, lately, a chance to prove all these things upon a natural- 
ist who believed, as has always been held, that "conspicuous" patterns, etc., 
make conspicuous objects. Of each species that he declared to be a con- 
spicuous one I arranged either a stuffed specimen or a good imitation, and 
placed it full in his sight, out of doors, in the most natural of situations. And 
each time he was amazed at failing to find it conspicuous. In every case of a 
series of such tests, he discovered the specimen only after a more or less long 
search. 

One case is enough to cite here. He declared a coral snake, with its red, 
black, and gold rings, to be "the most conspicuous object in Nature." I 
placed on bare ground some imitation snakes — one black, one scarlet, one 
gold, one earth-color, and one good facsimile of a coral snake, with its bright 
scarlet, gold, and black rings, and the counter shading universal among snakes, 
and invited him to look at them from a distance of about twelve yards. He 
saw at once all but the coral snake, and would never have known the latter 
was there had he not been told. Yet in this case he had been told just where 
to look, on a bare open space of flat ground. 

I asked him if he still believed that a naturalist's eye takes in most of the 
coral snakes that come within its range in the complex scenery of the jungle! 
By such experiments all his beliefs on the subject were one by one confuted, — 
as, in the end, he most openly and generously acknowledged. 

Concealing-coloration means coloration that matches the background. But 
since an object's background varies with the point of view, there can be 
no such thing as complete, intrinsic inconspicuousness. The means of ob- 
jects' recognizability, no matter how they are colored or marked, is almost 
always their silhouette — i. e., their outlines in 'relieving' darker or lighter 
or differently colored against their background. If an object moves about — 
or, what amounts to the same thing, if the beholder moves about — the object 
is bound to silhouette in various ways against various backgrounds. If the 

lo 



object moves about outdoors, in sunlight and in shadow, this versatility of 
silhouetting becomes extreme. Day's vast chiaroscuro can make the black- 
est objects 'relieve' bright against dark shadovsrs, and the whitest objects 
'relieve' shadowy dark against the light. Given a suflScient freedom of 
motion on the part of object or beholder, and, aside from changes in the 
object's own illumination, its backgrounds are bound to range through this 
whole scale of variations and contrasts, from earth and its darkest shadows 
to sky and its brightest lights. Patterns on animals' coats are the utmost that 
Nature can do in opposition to these potent vicissitudes of silhouetting. This 
is the point at which Darwin, Wallace, and others went wrong; and this in 
spite of the fact that their supposed "conspicuous" species are, doubtless, 
more easily detected, in the long run, than their "cryptic" species. It is 
true that if one sits still in a wild place one will usually detect more individuals 
of the so-called conspicuous kinds. Bu4^ this is because they are mostly ar- 
boreal or aerial species which a terrestrial observer is apt to see against a much 
wider gamut of background than that to which the so-called cryptics are sub- 
jected. They are the ones that have to move about most freely in sunlight 
and in shade, and against all manner of backgrounds, from shining sky to 
the darkest forest shadows. Their bold coloring, however, minimizes, not 
increases, their conspicuousness in this difficult situation, where the more 
nearly monochrome so-called cryptics, adapted for "sticking close" to tree 
trunks or the brown ground, would be comparatively conspicuous. One 
animal most needs to escape observation from above, another from below, 
and others equally from all directions. It follows that some must be colored 
to match brown ground, some to match the sky, or sky and foliage, while 
some must have costumes combining these extremes; and just such wonder- 
ful adaptations, in highest development, prove to be universal. Animals, 
therefore, are conspicuous when seen from any but the right viewpoint — white 
sky-matchers showing bright against the ground, brown earth-matchers sil- 
houetting dark against the sky, etc., — with all the magic of their concealing- 
costumes lost. Again, it follows that we should be inclined to count con- 

II 



spicuous those species which we most commonly see against the wrong back- 
ground. This is what Darwin and Wallace did, — and, failing to understand 
the effect both of pattern and of visibility through contrast and silhouette, 
they made the fundamental mistake of ascribing the conspicuousness to the 
very thing which opposes it. Their immense prestige has so riveted this 
error in students' minds as to have doomed the whole subject, hitherto, to 
confusion and neglect. 

Naturalists repeatedly experience the difficulty of detecting brilliantly 
colored birds and strongly marked quadrupeds — commonly recording each 
case as surprising or inexplicable under the supposed circumstances, or some- 
times manifesting a true apprehension of some one particular case, without 
seeing that they are dealing with a universal principle.* 

Among the aboriginal human races, the various war-paints, tattooings, 
head-decorations, and appendages, such as the long, erect mane of eagle 
feathers worn by North American Indians, — all these, whatever purposes their 
wearers believe they serve, do tend to 'obliterate^ them, precisely as similar 
devices 'obliterate' animals. 

The color-relations of earth, sky, water, and vegetation are practically 
the same the world over, and one may read on an animal's coat the main 
facts of his habits and habitat, without ever seeing him in his home. 

Abbott H. Thayer. 

MoNADNOCK, N. H., December 15, 1907. 

* Here is a simple way to discover whether one has the full color sense necessary as a basis for 
studying obliterative coloration. If, like a multitude of people, one cannot see that shadows on an 
open field of snow, or on a white sheet, under a blue sky, are bright blue like the sky overhead, one 
will probably prove more or less defective in all color-perceptions. To prove that such shadows 
are sky colored, lay a colorless mirror on the snow in such a shadow, — its reflected sky will match the 
surrounding snow. 



12 



CHAPTER I 

GENERAL OUTLINE OF THE BOOK'S SCOPE. THE "LAW WHICH UNDERLIES 
PROTECTIVE coloration" INTRODUCED 

PROTECTIVE COLORATION," with its achievement of the wonder- 
ful inconspicuousness of many wild animals in their native haunts, 
has been recognized since the earliest days of Natural History study. But the 
true character of this phenomenon has been ignored or misinterpreted, and 
the phenomenon itself has been observed only in one small corner of its wide 
field of action. It has waited for an artist, in the last years of the nineteenth 
century, not only to recognize the basic working lews of protective colora- 
tion, but to perceive that the many animals of supposed "cor picuous" 
attire are almost all colored and marked in the way most potent to conceal 
them. 

We will begin with an exposition of the long-ignored laws involved in such 
protective coloration as has been generally noticed, leaving to be developed 
in later chapters the revelation of its larger scope. 

Since time immemorial, human hunters must often have been aware of the 
strange elusiveness of motionless deer in a brown landscape, or of hares or 
partridges squatting on the ground. Those who stopped to seek the cause of 
this, perceived that the deer or partridge looked almost exactly like the land- 
scape or the ground in color, and were satisfied with this explanation; and 
thus was evolved that stock phrase of nature students, which has found a 
place in almost all books about animals, that these inconspicuous creatures 
are "colored like their surroundings." But it is our first task to show that 
this logical-seeming and universally accepted explanation is inadequate and 
misleading, and to vindicate the paradoxical-sounding statement that if crea- 

13 



tures were purely and simply "colored like their surroundings" they would not 
be inconspicuous at all. This has already been explained by articles in several 
scientific and popular magazines, but the explanation must be repeated here 
in full for the benefit of those who have not seen the former expositions of the 
discovery. What people commonly fail to perceive in connection with this 
matter, is that the exposition is really that of a discovery, i. e., of an indis- 
putable optical fact, hitherto unnoticed, and not merely that of one more 
theory. It is the revelation of how animals' wonderful inconspicuousness in 
their normal haunts, recognized for centuries but in its essence never under- 
stood, is really achieved. That is, not a description of any course of evolution 
or process of pigmentation, but the revelation of the manner in which the 
existent system of coloration renders animals nearly invisible on their native 
heath. 

I will quote, with slight modifications, from the original article published 
in 1896, and from that published in Nature in 1902. 

"The newly-discovered law in its application to animals may be stated 
thus: Animals are painted by Nature darkest on those parts which tend to be 
most lighted by the sky's light, and vice versa. The accompanying diagram 
illustrates this statement. 




"Animals are colored by Nature as in A, the sky lights them as in B, and 
the two effects cancel each other, as in C. The result is that their grada- 
tion of light-and-shade, by which opaque solid objects manifest themselves to 
the eye, is effaced at every point, the cancellation being as complete at one 

14 



point as another, as in C of the diagram, and the spectator seems to see right 
through the space really occupied by an opaque animal." In the Nature 
article this was reworded and emphasized as follows: "If an object be colored 
so that its tones constitute a gradation of shading and of coloring counter to 
the gradation of shading and of coloring which light thrown upon it would 
produce, and having the same rate of gradation,- such object will appear 
perfectly flat; — retaining its length and breadth, but losing all appearance of 
thickness; and when seen against a background of color and pattern like its 
own will be essentially indistinguishable at a short distance. All persons 
who have seen the models which illustrate this, know that they prove it. 
Now, if this stands proved, the fact that a vast majority of creatures of the 
whole animal kingdom wear this gradation, developed to an exquisitely mi- 
nute degree, and are famous for being hard to see in their homes, speaks for 
itself. It is plain that their color-gradation can no more escape effacing 
their look of solidity than the law of gravitation can escape drawing a pro- 
jectile to the earth. This is so obvious, that one hears on all sides expressions 
of wonder that it was so long unnoticed. I may add that all persons of trained 
sight, such as artists, perceive it everywhere among wild creatures. Other 
people supplement their undeveloped sight-sense by their other senses, and 
if they know an animal is solid, think he looks solid. 

"Let anyone look at a ball, or egg-shaped object, an)rwhere out of doors, 
and when he has recognized its shading, from its light side to its dark, try to 
so color it, where it stands, as to efface this shading. If he succeed, he will 
find that Nature has swiftly guided him through the same process which has 
taken her so long on the coats of animals, and that he has given the object the 
counter-gradation I speak of; and it will have dawned on him that so long as 
light makes its one gradation on objects, there is only the one way to neutralize 
it. In short, I simply prove that this arrangement of animals' colors is what 
so marvellously effaces them, and leave it to others to discuss the question 
whether concealment be a benefit to an animal, and whether the fact that it is 
a benefit be the cause of his being concealed. All who believe in Natural 

15 



Selection, however, will of course feel that this color-law is its work; and 
since it is so almost universally in use, and accounts, apparently, so almost 
exhaustively, for all the attributes of graded animal coloring, I believe it will 
ultimately be recognized as the most wonderful form of Darwin's great law." 

The foregoing extracts together fully state the newly-revealed principle, 
which in its various elaborations is the foremost subject of the present book. 
But it may be well before going further to dwell at greater length on the sim- 
plest aspect of this fundamental principle. 

No one who has studied animals in nature can have failed to notice either 
their frequent wonderful inconspicuousness, or the fact that ninety-nine per 
cent of them are dark colored on the back and light colored on the underside. 
On the other hand, even school children are daily taught that the only way 
to draw a representation of a ball or cylinder is to shade it from a bright 
central point or middle line to dark borders — or, if the object is to be shown 
in side view, under a top light, to shade it from very bright above to deeply 
dark below. Yet the obvious conclusion that the contrary gradation of 
shades, as it exists on the rotund bodies of animals, is the cause of their wonder- 
fully unsubstantial appearance, has never been drawn till now, and even now 
is but slowly accepted by most people. This is because few people recognize 
the vast part played in the visible world by light-and-shade. As has already 
been said, the known fact 0} solidity suffices, to many minds, without any 
inquiry into the means by which that solidity is manifest to their sight. Light- 
and-shade, color, and line, are the three great factors of visibility. Line 
perspective enables the eye to judge to a large degree of the forms of objects, 
and the various distances of their different parts, especially in the case of large 
ones of elaborate shape, such as buildings; but the visibility of line is de- 
pendent on color, and still more on light-and-shade. I here use 'line' to 
mean the visibility of the boundaries of material surfaces and their parts. 
It is obvious that this is dependent on color, since if a monochrome flat sur- 
face is so placed relative to the eye of an observer that one of its boundaries 
is against another flat surface of precisely the same color, and similarly lighted, 

16 



that boundary will be invisible; and it is just as evident that it is dependent 
on light-and-shade, since two objects of like color can be differentiated, and 
two of different colors can be made to appear to blend together, by effects 
of shadow and light. Light-and-shade is more important than color, because 
it is primarily an attribute of form, while color is only secondarily so. The 
reader should look at his hand, or any other small object of elaborate form, 
and consider the factors of its appearance which enable his eye to perceive 
it, in its entirety and its details. The form and position of the various por- 
tions are revealed by the lines of perspective, and by the light-and-shade, 
that is, the shadows on those parts which are most averted from the prevailing 
light, and the points of high-light on the reverse portions. We have already 
seen that these main factors are interdependent on each other. Color, the 
third factor, plays a much smaller part. A projecting portion, for instance, 
may be of a different color from the rest, and will then be distinguishable 
from it by its color alone, but without the line and light-and-shade it would 
appear merely as a spot of color on the general surface — the projection would 
not show as such, except in so far as its peculiar color revealed its character- 
istic outline, — when, as in the case of the counter-shaded animal, the fact of 
its solid form would be mentally inferred, rather than actually seen, by the 
observer. On the other hand, there is the color difference between the sur- 
faces which more directly catch the bluish sky-light, and the relatively orange- 
colored shadow-portions, etc., aside from other possible color incidents of 
reflected light; but these are secondary factors, since if the whole object were 
of a uniform neutral tint, and the color effects of the light were eliminated, 
the visibility of its various parts would scarcely be decreased. (Drawings in 
black and white, and photographs, are excellent exponents of this principle.) 
In just this way the form-variations of all solid objects are revealed to the eye 
— according to the simple law, that depressions lose light and are therefore 
darker, and elevations gain light and are therefore brighter; surfaces averted 
from the prevailing light being equivalent to depressions, and those turned 
toward it to elevations. It is, then, primarily by the light-and-shade on solid 

17 



objects, that the eye is made aware of their existence, their main form, their 
position, and all their minor modelings. Now, since this is the case, it follows 
that animals, however colored, would always be more or less conspicuous in 
their natural environment, and all the details of their form would be dis- 
tinctly visible, unless their surfaces bore such an arrangement of light and 
dark shading of the colors as could counteract the shading which the de- 
scending daylight applies to their solid bodies. This counter gradation of 
shades, from dark mid-backs to white mid-bellies, is, as we have seen, pre- 
cisely the system of coloration ('Mimicry' — vide Chapter II — aside) of 
almost all protectively colored animals. 

The ghostly elusiveness of a counter-shaded creature's appearance is at 
its best under a diffused sky-light, such as that in the forest, or the open fields 
on a cloudy day, because no color gradation can adequately cope with the 
full and concentrated light of the sun itself, which produces sharply contrasted 
areas of light and shadow, rather than a graduated shading. Even in full 
sunlight, however, the light from the wide expanse of sky is still the principal 
factor. To understand this, the reader should compare the difference between 
a sunlit patch of ground and a neighboring one which is cut off from the direct 
sunlight, with the difference between the latter and the mouth of a deep hole 
which is cut off from both sun- and sky-light. The one is the slight difference 
between a sunny and a shady spot, the other is the vast difference between 
night and day. A patch of bright sky no bigger than the sun is far less brilliant, 
but the vast sum of such patches which the entire expanse of sky contains, 
yield a far greater light than the sun itself. (This is analogous to the principle 
of sound, which makes the sum of the concurrent echoes of a clap of thunder 
far louder than the initial sharp electrical report itself.) An animal's 
counter shading, then, is effective even on open ground on a sunny day, 
although the superadded direct sunlight interferes with the perfection of 
its working. 

On this basis of the obliteration of the light-and-shade aspects of a solid 
creature, the most exquisite color resemblances to the creature's background 

i8 



are achieved; on no other basis could they be achieved, or would they greatly 
avail the animal. (See, however, the definition of Mimicry in Chapter II.) 
The reader who has assimilated what we have said thus far, is now in a 
position to perceive the fallacy of the statement, prevalent in former years, 
and still made by certain writers, that a protectively colored animal of the 
type described above escapes detection because, being of a dull-brown color 
like the ground and the bushes, it looks when it sits motionless like a clod or a 
stump — or some such inanimate thing. For clods and stumps are solid 
objects of a uniform tint, and manifest to the eye, by the laws of light-and- 
shade, not only their solidity, but all their smaller modelings. They are not 
inconspicuous, except in so far as their great abundance makes the eye in- 
attentive to individual ones. The protectively colored animal, on the other 
hand, is, as it were, obliterated by his counter-gradation of shades, and in 
the cases where he escapes notice, it is by virtue, not of the eye's perceiving 
his solid form, and taking it for that of an inanimate object, but of its failure 
to recognize it as a solid object of any kind, seeming, if it rests on it at all, 
to see through it to what is beyond. For the animal looks at most like a flat 
plane interposed between its background and the observer; and since actual 
flat foreground-planes of this kind at right angles to the earth do not com- 
monly exist in the woods and fields, the eye usually interprets the animal's 
surface as part of the scene, ground-plane or wood mass, simple or com- 
pound, which lies beyond it. If these animals were merely brown or gray 
like clods and stumps, they would not be concealed, because their structural 
forms are too distinct, and the eyes of enemies are keen to detect their charac- 
teristic 'modeling* and outlines. On the other hand, a perfect shade- 
gradation, even of some rankly brilliant color, would go far toward concealing 
an animal, for he would still have no appearance of solidity; and any varied 
landscape, especially a sunlit one, even in the dingy temperate zone, is full 
of patches of brilliant color, as all artists know.* 

* A large expanse of any strong color, as the green of the foliage, begets in its interstices and on 
its borders an appearance of its "complementary." It is partly for this reason, as an American 

19 



A striking revelation of how completely the inconspicuousness of counter- 
shaded creatures depends upon their counter shading, may be had even more 
easily than by experimenting with models, merely by holding such a creature 
upside down, in its normal lighting, and against its normal background. It 
will be seen not merely that its ghostly dimness has vanished, but that it is 
extraordinarily conspicuous — ^just doubly as conspicuous, in fact, as any stick 
or clod placed in the same position would be. For an inverted animal not 
only lacks counter shading, as a stick or clod does, but is even fully shaded 
the wrong way — ^brightest where it catches most light, and darkest where it 
catches least. No other conceivable arrangement of colors could make an 
object as conspicuous as this. Yet an animal held thus inverted is, materially, 
as truly "colored like his surroundings" as he ever was. It might be thought 
that such creatures are usually seen from above, so that their light-colored 
undersides are out of sight, and that only their upper parts, which always 
show, are supposed to be colored like their surroundings. To this there are 
two cogent answers: In the first place, many of these creatures, such as the 
various forest Grouse, are at their best when perched high above the ground, 
so that the under side is at least as fully exposed as the upper. In the second 
place, the colors of those which stay on the ground must surely serve as a 
protection against the ground a-nimals, which move about on their own level, 
as much as against those which see them from above, as do hawks and men. 
This last is a very important consideration, with which we shall have to deal 
again later in the book. 

In speaking of the elements of visibility, I have already referred to the fact 
that color — apart from light-and-shade — is a secondary factor in the visibility 
of the 'modeling' of solid objects, and have spoken of the tendency toward 
a bluish coloring of the more directly sky-lighted portions, and an orange 
coloring of the reverse ones. The working of this principle on the bodies of 
animals is very pronounced, and the counter gradation of their tones would 

ornithologist, Mrs. F. H. Eckstorm, has very truly said, that the gorgeous Scarlet Tanager is not 
conspicuous in the green woods. 

20 



not be perfect if it did not include a delicate gradation of actual color, from 
brownest above to bluest below, to cancel the effect of the bluish sky-light 
and shine on their upper surfaces, and the brownish shadow, with brown earth- 
reflections, on their lower. Cold white is usually required for the bright 
climax of the shade gradation, and cold white amply meets the color require- 
ment also. It is likely that few but artists will feel the validness of our state- 
ment of this subtler element of the principle, although anyone can learn to 
see the existent gradation of 'color' on most counter-shaded animals. 

The reader has now been given a fairly exhaustive description of the main 
elements of the new principle, which through its various windings and with its 
various remarkable concomitants we are about to follow into several branches 
•of the animal kingdom. Among the lower orders, it is more or less largely 
supplanted by another great principle, namely, that of Mimicry, which we 
will define and differentiate in Chapter II. 

Before closing this introductory chapter, however, we must give an account 
of the earlier, independent partial discovery of the principle of counter shading 
in the animal kingdom, by Prof. Edward B. Poulton, of Oxford University. 
Professor Poulton has been one of my father's most enthusiastic listeners, 
and is one of the few naturalists who have given proof of completely under- 
standing the subject. In his introduction to my father's article in Nature 
he generously seeks to minimize the importance of his own partial predis- 
covery of the principle. 

The case is thus stated by my father in the above-mentioned article: 

"Since publishing my papers in 'The Auk' for April and October, 1896, 
I find that Prof. Poulton perceived years before their appearance the power 
of a counter-grading of light to make the round surface of a pupa appear 
flat, and in another case the power of light color in a depression to make the 
concavity disappear. In both of these cases he perceived the very Law of 
Light-and-Shade on which the fact of Protective Coloration rests, and recognized 
the fact itself in these instances. In his 'Notes in 1886 upon Lepidopterous 
Larvae, etc.,' read April 6, 1887, he says (Trans. Ent. Soc. Lond., 1887, p. 

21 



294), 'Although the cleft (between the posterior part of the body of the larva 
of Rumia cratcBgata and the branch) is largely filled up, ... a considerable 
furrow remains, but this is not apparent because of the light color of the 
fleshy processes, which prevent the attention from being directed to the shadow 
which would otherwise indicate the position of the groove. The processes, 
therefore, attain the object of softening the contact between the larva and 
its food-plant in a two-fold manner, by partially filling up the cleft and by 
neutralizing the shadow in the groove which remains. I have also noted the 
processes in the larva of ^. betularia, and I believe that they are of very general 
occurrence in Geometrae.' 

"His other case is to be found in his 'Notes in 1887 upon Lepidopterous 
Larvae, etc.,' read October 3, 1888. He says (Trans. Ent. Soc. Lond., pp. 
595-6), 'The most extraordinary thing about this resemblance (of the pupa 
of Apatura iris to a sallow-leaf) was the leaf-like impression of flatness con- 
veyed by a pupa which was in reality very far from flat. Thus the length 
of the pupa was 30.5 mm.; the greatest breadth (dorso- ventral diameter) 
1 1. 5 mm.; the greatest thickness (from side to side) 8.5 mm.; . . . But 
exactly in these places, where the obvious thickness would destroy the re- 
semblance to a leaf, the whole effect of the roundness is neutralized by the 
increasing lightness of these parts — a lightness which is so disposed as to 
just compensate for the shadow by which alone we judge of the roundness of 
small objects. (Much larger objects can be judged of by the change of 
focus, which becomes necessary as their near or distant parts are observed.) 
In shading the drawing of an object so as to represent roundness, the shade 
is made to become gradually less and less deep as the tangential planes repre- 
sented come nearer and nearer to a right angle with the axis of vision. So 
here, the converse of shading— the whiteness neutralizing the shadow which 
shading is intended to represent — dies off graduaUy as the (representation of 
the) mid-rib is approached. 

" 'The whiteness is produced by the relative abundance of white dots and 
a fine white marking of the surface which is present everywhere, mingled with 

22 



the green. The effect is, in fact, produced by a process exactly analogous 
to stippling. 

"'By this beautiful and simple method a pupa, which is 8.5 mm. from 
side to side in its thickest part, appears flat and offers the most remarkable 
resemblance to a leaf which is a small fraction of i mm. in thickness.' " 



23 



CHAPTER II 

DEFINITION OF TERMS. ILLUSTRATIONS OF OBLITERATIVE COLORATION 

BEFORE going further we must clearly establish and define the special 
descriptive terms which are to be used in the course of the book. 
The term, "the law which underlies protective coloration," as applied to 
counter shading, was inexact, since "Protective Coloration" of course includes 
not only concealing-colors based on this newly disclosed principle, but many 
branches of the entirely different principle of Mimicry, as weU.* A name 
even more to our present purpose than Protective Coloration, for the com- 
prehensive meaning, would be one which should include all modifications of 
the bodies of animals, both those of form and those of color, whose ob- 
ject seems to be visual deception of any kind. This would make room for 
offensive as well as defensive mimetic resemblances, etc., and for the many 
curious cases of protective form modification, most common among the lower 
orders of animals. But we are to have so little to do with these partially 
extraneous principles that we need not discard the old and familiar term, Pro- 
tective Coloration. Interchangeably with it, however, we shall use others some- 
what more comprehensive, viz.. Disguising Coloration and Disguising Costumes. 

* Throughout our book we shall use the word Mimicry in a wider and perhaps looser sense 
than that in established use among zoologists, and we herewith offer an apology for this innovation. 
In order to emphasize tersely the fundamental difference between 'Obliterative Coloration' and 
both the principles involving imitation of definite objects, which principles have been known re- 
spectively as Mimicry and Protective Resemblance, we have found it necessary to join the two last 
mentioned under the general head of Mimicry. Derivatively, the name is nearly as applicable to 
one as to the other, and the limiting it to the simulation of the colors and forms of animate creatures 
by those of other animate creatures, in contradistinction to the imitation of inanimate objects, is more 
or less arbitrary. The two phases are closely related, and for our present purposes must be consid- 
ered as different branches of one principle, which can only be called Mimicry. 

24 





Kn;. 1. Two biicUnioclels, just 
ulikc except that the one on the left 
is eon liter-shaded, the other not, 
tlioii^Ii covered uniformly with the 
vmy uiatorial of its hackgroiuid. 
This ri.sht-hand model, therefore, 
is tirliiaihj as light helow as above. 



r[f;. :;. liinl-iiinilc'K a^ in Fig. I, 
but with the top-light cut ofl froTii 
the iihlitt ratively-shaded one, A. 




l-'ir.. 2. Obliteratively-shadcd bird-nifKk'l. 
as ill Fig. lA, but iiiverted. (Sniiicwhat 
huU'-lightod.) 




Via. 4. Two hird-models as in J''ig. 1, hut out of doors against 
hare ground. The one on the right is obliteratively-shaded, tlu- 
other nut. 




Fig. 5. Two bird-models jireeisely as above save that the 
right hand one is still better 'obliterated.' The reader will 
have to take it on faith that this is a genuine photograph, and 
that there is a right-hand model of the same size as the other, 
unless he can detect its position by its faint visibility in Fig. -t. 



Protective or Disguising Coloration, then, as we define it, falls into two 
main divisions; the one including concealing-colors mainly based on counter 
shading, and the other including Mimicry, in almost all its branches. As 
has already been explained, the goal of the former principle is the rendering 
animals invisible in their normal haunts. Mimicry, on the other hand, aims 
at deceptive visibility; it makes an animal look like something else than what it 
really is. It will be seen that the latter principle is open to unlimited varia- 
tions of method and result, whereas the former, as we have proved, is in its 
main essentials strictly limited. There are innumerable kinds of solid objects 
for animals to simulate in appearance, but there is only one way to make a 
solid object in a natural lighting cease to appear to exist. Both these are 
principles of disguising costume, and both are protective, yet they are funda- 
mentally unlike. It becomes necessary to find a fully adequate name for the 
stricter principle — a name less technical and more explicit than "counter 
gradation." Obliterative Coloration is a phrase that will fit the general 
principle, and Obliterative or Counter Shading may be used as a stricter term 
for the essential root of it. 

We have, then, Obliterative Coloration, and Mimicry, as the two main prin- 
ciples of Protective Coloration. Of the well-known and well-studied prin- 
ciple of Mimicry, we shall give but few examples, and these chiefly from 
among the lower orders. In the higher orders, it seems, as we have said, to 
play a very insignificant part. 

Figs. 1-5 illustrate obliterative shading, pure and simple. Fig. i shows 
an obliteratively shaded artificial model, contrasted with a monochrome one 
which is colored precisely like the background, being covered with the very 
same material; Fig. 2 shows a counter-shaded model inverted, and Fig. 3 
the two models in the proper position, but with the direct top-light cut off 
from the counter-shaded one. 

Fig. 6 shows a Barred Plymouth Rock hen, a bird which completely lacks 
obliterative shading, photographed, out of doors, against a background made 
wholly of the flat skins of similar hens. A more striking demonstration of 

25 



the powerlessness of mere similar colors to conceal could hardly be devised. 
So, were it not for his obliterative shading, would the leopard or jaguar show 
up in the forest, despite his richly spotted forest-pattern. 

Fig. 7 shows a pure white hen, photographed against a white cloth, an- 
other illustration of the ineffectuality of mere color-resemblance. The hen 
is conspicuously solid, her back showing light and her belly dark against the 
flat white plane of the cloth. Every part of her surface, in fact, except for a 
few mere points of transition, is either too dark or too light to match her back- 
ground. A ptarmigan in winter plumage lacks the advantage of counter 
shading, and must needs lack it, since even the middle of its back has to be 
white to match its pure white snowy background, and nature can furnish 
nothing lighter than white feathers for the bird's underside. But the up- 
ward reflection from the snow itself goes far toward canceling the shadow 
on such animals. (See Figs. 8-10.) In the same way the reflection from 
bright sand cooperates with the delicate counter shading of desert animals, 
which are usually very light colored. Such creatures are also as a rule al- 
most unmarked, and thus furnish good examples of the use of obliterative 
shading, pure and simple. It is on a delicate scale, however, since there is 
but a short range of shade between pure white and the delicate brown re- 
quired to make the animals' backs 'coalesce' with the sand. Desert animals 
are of course habitually exposed to full sunlight, but the excess of shadow 
which the undersides of sunlit animals normally bear,* is in this case almost 
or quite counteracted by the light-reflecting power of the bright desert sand. 
Many forest animals, on the other hand, wear a slight counter shading at the 
dark end of the scale— that is, from some dark color to a very slightly lighter 
tone — because of the extreme diffuseness of the light in shady forest recesses, 
whose colors are mainly dark and rich. The need of extreme counter shading 
— from very dark to purest white — seems restricted mainly to high-standing 
animals which live in the open on dark ground. On such a one the direct 
sky-light makes its fuU graduated shading, and the shadow of the undersides 

*See p. 18, Chapter I. 
26 















t 


^^HPHH 









Fig. 6. Plymouth Rock hen— a bird which lacks counter-shading— against a flat background of 
Plymouth Eoc;k hen skins, demonstrating the same thing as Fig. 7. 

Photographed from life. 




Fi'- '■ J^'''^" J?7'' }^S^™« counter-shading, against a flat white cloth. To show that a monochrome 
object can not be 'obhterated,' no matter what its backgronnd. u^i.iuun, 

Photogi'aphed from life. 




^ 





Fig. 8. Kooky Mountain White-tailed 
Ptarmigan in winter plumage, on snow, and 
faTorably lighted for inconspicuousness. 
Rotundity as dimly apparent as is possible 
without counter-shading. 

Photographed from life by Edward R. Warren. 




Fig. 9 Eocky Mountain White-tailed Ptarmigan, in winter plu- 
mage, off snow. Their rotundity, revealed by their lack of counter- 
shading, 13 marked. But they may still pass for lumps of snow. 
Photographed from life hy E. R. Warren. 




unfa^/o^ra^ryli^Sff^l-i^Xi^t'et^* '''^™'^^" ^ -'"'" >"-='S^. - -»-. ^--t 

Photographed from life by E. R. Warren. 



is not alleviated by upward reflection; while the highly illuminated back has 
to be of a very dark tone to coalesce with the dark earth, rock, or whatever 
it may be that forms the animal's normal background. 

These examples serve to illustrate the law, almost or quite infallible, that 
the range and scale of an obliteratively colored animal's counter shading de- 
pend on the ratio of the average brightness above it to the average darkness 
beneath it, in its normal haunts. Thus, to recapitulate, we find on sandy 
deserts birds, mammals, and reptiles counter-shaded from sand-color to 
white, while on dark-colored open ground we find them shaded from very 
dark to white. (Of this last class the smaller Wood Sandpipers (Totanus), 
which live on muddy stream and pond banks, are excellent examples. So 
also, in a cruder form, are some of the Oyster-catchers (Hcematopus) and 
Stilts (Himantopus), whose counter shading consists of two tones only, black 
and white. Among mammals, examples are the darker-backed hares, deer, 
kangaroos, etc., which live more or less fully exposed to the sky-light on rather 
dark ground.) Where the sky-light is intercepted and diffused by foliage or 
other natural obstructions, as on the ground under grasses, bushes, etc., on 
marsh-land under reeds and rushes, and, most of all, in the forest, we find 
many rich or dark-colored animals with a weak obliterative shading (one, 
namely, whose bright climax comes more or less short of white, being even in 
some cases but slightly lighter than the tone of the back). Many of the for- 
est-inhabiting passerine birds of Europe and America wear this form of coun- 
ter shading, as do also certain forest grouse, as well as squirrels and other 
mammals; while among tropical birds it is well represented by many green 
parrots and parrakeets, etc., and also by many brown species that inhabit the 
gloomy interiors of the great forests. Some of the ground sparrows, and the 
rails, are good examples of the grass and swamp forms, while the female of 
the European Blackbird (Merula), and the North American Catbird {Galeo- 
scoptes) may be cited as examples of the thicket-haunting form among fa- 
miliar birds. This indisputable fact, that animals tend to be dark in thickets 
and dusky forests, and pale on the glaring desert, and on ocean beaches, is a 

27 



complete refutation of the theory that the counter shading is due to the tan- 
ning effect of light. On the other hand, the idea that the paleness of desert 
creatures is due to bleaching, is equally well answered by the fact that their 
shadowed undersides are still the lightest, as in the case of almost all other 
animals. 

Figs. 11-13 show photographs of the skins of various birds and mammals, 
split longitudinally through the lower median line, and spread out fiat. This 
is a simple and adequate way of exhibiting the exact character of the obliter- 
ative shading of animals. The names of the species thus represented are 
given under the pictures. It will be seen that some beasts which are usually 
considered practically monochrome, such as the Mink {Putorius vison), have 
in reality a slight counter shading. (See footnote, p. 123.) 

Pictures of protectively colored wild birds and mammals in situ cannot be 
really true to Nature if they represent them as having the light-and-shade of 
normal solid objects — a fault usually committed by illustrators, who study 
them in unnatural situations, such as the cages of a menagerie, or other places 
where the illumination fails to cooperate with their counter shading. These 
paintings of ours (grouse, rabbit, snake, caterpillars, etc.) are intended as 
examples (outside the field of photography) of true animal illustration — ^ren- 
dering instead of defeating the wonderful obliterative effects of their counter 
shading.* 

Of course so new a lesson cannot be learned all at once by the world at 
large. But when the truth on any subject has once been started, it cannot 
fail gradually to supplant the previously existing errors. It will be many 

* Japanese and Chinese art almost entirely dispenses with light and shade, dealing solely with 
line and color. Japanese pictures of birds and mammals, therefore, represent, approximately, the 
animal's actual color tones, quite irrespective of shading. A white belly, for instance, is painted as 
bright as a white back. Thus these Oriental renderings of animals are actually, in one sense, more 
realistic than the Occidental, because by their complete lack of shading they approximate the won- 
derfully unsubstantial look of the birds and beasts in Nature. An object which shows lighter on its 
lower border than its upper, under the light of the sky, cannot possibly look solid. It looks at most 
like a party-colored flat (or concave) surface, rather than a rotund body. 

28 



n 




1 


^^ff <^ "' '■^^BlB 


.. '"'^n^ 

i'^»^ 


■. ^ 


Jm 




W '^ 




^R>/ ' . ^ 


.■I . .i''l^PL -- 


ItJ.'tj^a,-!---'^-- ■ ** 






(j'^^^^V'-^^^^^HH 




g-^^^^HF 'j^.'^SB^^HH 


i^!«^wB 


'^r:f 


r-; 




» 


' ill;' 


m -. 


^ffl« 


ffia 




fiMLJn f^HftH 


%i ^. ,.i^ 


,• JJK"^.^ '■-.'<' ^^ 


ra^B^7 


r ^ ' 


m j^r 


k ^ 


B Jl^^ 


^*^i 


P.^j . ; 


pm ^w^ 


1^ 






1 


1^ ^>-,i'#v 


:l 


■1 


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Figs. 11 and 12. Mammals' 
skins spread out to show oblit- 
erative-shading. 

Fig. 11. Spotted Seal {Phoca 
vitulina.) 

Fig. 12. Cotton-tail Rabbit 
{Ijmus floridanvs tranaitionalis.) 
[CfT above.] 



Fig. 13. Birds' and mammals' skins spread out to show obliterative-shading, continued. The 
species are as follows: Beginning above, left, Blue Jay {Cyanoeitta cristata), Tree Swallow {Tachycinetta 
bicolor)f Pine Grosbeak {Plnicola enucleator canadensis, female), Common Chipmunk {Tamins striatus) 
Mink {PatoHus vison), English Sparrow {Passer domesHcus, female), Lesser Whitethroat (Sylvia citr- 
I'uca), two kinds of shrew-mole, names (?) jumping mouse {Zapus hvdsoniiis, stuffed skin side view) 
Am. Siskin (Spmus pmus) , Gray Squirrel (A'cruriM caroiiwenffw), Muskrat {Fiber zihetUeus) and sharp- 
shinned Hawk {Accvpiter velox, young female). ' 



years, no doubt, before a drawing with conspicuous light-and-shade of a live 
sandpiper or rabbit in Nature is looked upon as an absurdity — and yet that 
time must surely come. 

Having considered obliterative shading, pure and simple, we will now 
advance to the next stage in the study of obliterative coloration, namely, the 
use of markings on counter-shaded animals. 

The first few chapters will deal chiefly with artificial models. 



29 



CHAPTER III 

FIRST PKINCIPLES OF THE USE OF MARKINGS WITH OBLITERATIVE SHADING 

THE need of markings is a natural concomitant of the principle of ob- 
literative shading. When an unmarked solid object in a given lighting 
has been reduced to a perfectly 'flat' monochrome by counter shading, so 
that it lacks all visible attributes of solidity, it may be quite undistinguishable, 
provided that its background is 0} a similar monochrome flat tint. Such is the 
case in Fig. 14. The solid model is almost undistinguishable, seeming merged 
into the flat plane of the cloth-covered board, which in reality is several yards 
behind it. 

Complete 'obliteration' has taken place; for the model, having no dis- 
tinctive light-and-shade, color, or surface character, is as it were absorbed 
into its background, and the space in which it stands seems occupied by empty 
air. But if we now apply a pattern to the background, as in Fig. 15, the case 
is changed. Though still unsubstantial-looking, and very inconspicuous, the 
model is clearly discernible as an interruption of the background- pattern. If 
this pattern is small and regular, as in our figure, the whole of the unmarked 
object's characteristic outline may be traced against it, and by the process of 
mental inference already alluded to, the observer will recognize it, in spite of 
its ghostly flatness, as a solid body between him and the background-plane. 
But behold the effect of applying a like pattern to the model also, as in Fig. 
16! It immediately recedes again into the flat plane, and the eye loses it even 
more surely than before, because its likeness to its background is now positive 
and graphic, at many points. 

The foregoing figures illustrate the simplest form of the use of markings 
in cooperation with obliterative shading. The next thing for us to consider 

30 




$^>;-;-,, 



Fig. 14, Obliteratively-shaded bird-shaped 
model against plain background. (Defective 
photograph, retouched. The model might 
show even less, in reality. Ct. Figs. 4-.i.) 














' >■ 



v^\M>^'^'^^^-^ 



Fig. 15. Bird-shaped solid iiiodt-l, 
obliteratively-shaded in full, and 
i-on-eclly lighted, but revealed by its 
blank silhouette against a spotted 
Vjackground. 

Photograph. 



■w* 



Ym. K), Bird-shaped, oblitera- 
tively-shaded model, as in Fig. lo, 
but concealed by the addition of 
spots like tho.'^c of its background. 
Phototfi-apD. 



Fig. 17. Spotted, obliteratively-.shadcd 
bird-model, as in Fig, 3(>, but wroiijily 
lighted. This picture shows the (h'jicnti- 
f'lice of the part played by pattern in the 
obliteration of leopards, zebras, etc. 
Without counter-shading, these animals 
would look conspicuously solid, despite 
their patterns. 




is the matter of pattern perspective. The elucidation of this will mark another 
step in the differentiation of obliterative coloration from all forms of mimicry. 
For it will show that not an exact reproduction of the actual background- 
pattern, but a picture of that pattern as it looks when more or less altered and 
refined by distance, is essential to the concealing of an object. Or, in other 
words, that the object's obliteratively-shaded surface must bear a picture of 
such background as would be seen through it if it were transparent. The 
diagram, Fig. i8, represents a flat, bird-shaped model, vertically placed, 
seen against a horizontal background. The background-pattern is supposed 
to be actually uniform throughout, but diminished to the eye as it recedes on 
the horizontal plane. The model, vertically interposed between the eye and 
this receding ground-plafie, must, for concealment, bear a pattern graduated 
from larger on its lower borders to smaller on its upper. For the highest 
parts of the model are seen against the most distant and therefore most dimin- 
ished portion 6f the uniform background-pattern — and vice versa. Further- 
more, the markings of the background, being on a receding plane, are fore- 
shortened throughout, and this effect also must be imitated on the model. 

These diagrams and photographs will serve to illustrate, in a crudely sim- 
plified form, some of the main principles of obliterative pattern which prevail 
in Nature. Instead of one unvaried pattern on a single plane, however. Nature 
furnishes backgrounds of rich diversity. Mud, grasses, pebbles, bushes, tree- 
trunks, branches, leaves, living and dead, and vistas amid vegetation to the 
bright sky beyond — these, all of them subject to endless variations of com- 
minglement, of distance, and of lighting, are a few of the numberless details 
of the backgrounds against which ground-haunting animals are seen. To 
achieve the highest degree of inconspicuousness, these animals must wear, 
superadded to their obliterative shading, yet in the main conforming with it, a 
sort of compound picture of their normal backgrounds — a picture seemingly 
made up by the averaging of innumerable landscapes. Further, this land- 
scape-picturing must be suited variously to different portions of the animal's 
surface. The top-planes, being seen in full only against the nearer ground, 

31 



must bear a larger pattern than the sides (see the second diagram, Fig. 19), 
which are seen against more distant ground or forest landscape, with details 
reduced and altered by perspective ; and the highest portions of the side-planes, 
e. g., the sides of the animal's head, being seen, in the long run, against the 
most distant backgrounds, must have the finest pattern of all. Cooperant 
with these principles is the fact that the pattern looks different on receding 
planes of the solid object. Thus in the side view all that shows of the neces- 
sarily coarser top-pattern is so refined and narrowed by perspective that it is 
fully equivalent to the actually finer pattern of the sides. In the reverse case, 
the side-pattern scarcely shows at all. 

Nature's achievement of this ultimate perfection of obliterative coloration, 
on birds, is the subject of our next chapters. 



32 



- :!.■ II >,(■---,- 










l"in 18 Diagraiu sliowhig the piftnriiig of iicvspective by animals 
patterns. The bird is supposed to be % pitically placed, and hwked some- 
what lUwii upon against a uniformly patterned horizontal ground-plane. 




Fig. 19. Diagram supplenieutiiig Fig. 18, showing the 
coarser Sacft-pa'tteni, required to match the ground- 
pattern un-fore.5hortened and almost undiminished, as 



patte-- -- 

when seen from directly above. 





Fig. 21. Shows particularly well the head-markings 
picturing of a shadowed cavity crossed by lighted twig 
or grasses. 



Figs. 20-21. American Woodcock on its nest; showing the working of the wonderful obliterative picture-patterns, founded on counter- 
shading. 











■ C i 




CHAPTER IV 

BACKGROUND-PICTTIRING ON OBLITERATIVELY-SHADED BIRDS. FIRST TYPE, 
PICTURING OF THE LARGER DETAILS OF THE NEARER GROUND, ON 
TERRESTRIAL BIRDS 

HEREWITH we leave the arid field of demonstration with artificial 
models, and launch into the wonderland of actual Nature. If we 
compare the numerous cases of evident background-picturing on the bodies 
of obliteratively-shaded birds, we find that they are clearly separable into 
several main classes or divisions. Many of the species, for instance, have a 
wonderfully minute and intricate pattern, while others, almost equally famous 
for their 'invisibility,' are marked in a much simpler and more blotchy 
way. The finely-patterned class is again divisible into two very different 
branches, as we shall see later on. This chapter, as the heading indicates, 
is to be devoted to the more blotchily-marked type of pattern-bearing 'In- 
visibles.' The best examples of this type are terrestrial birds which live 
among fallen leaves and sticks, etc., or among weeds and grasses, patches of 
mud, and pools of water. Preeminent among them are the Snipes and 
Woodcocks {Philohela, Gallinago, etc.), — ^Figs. 20-26. 

The American Woodcock {Philohela minor) is a beautiful representative 
of the class. See Figs. 20-22, reproduced from photographs of live Wood- 
cocks in Nature, and Figs. 23-24, which show photographs of a dead Wood- 
cock against a normal background, but with its obliterative shading variously 
upset. In Fig. 24A, the bird is on its side, with its back toward the spectator. 
Thus the largest expanse of its pattern is exposed to view, yet it completely 
fails to obliterate, chiefly because it is no loiiger aided by a proper light-and- 
shade gradation. Fig. 24B shows the same bird with under instead of upper 
side exposed — in which position it is of course even more conspicuous. Fig. 



23 shows the bird, with the general shade of its back artificially extended over 
its sides and belly, posed to simulate as nearly as possible the attitude of the 
live bird on its nest represented in Fig. 22. The contrast between the two, 
as to conspicuousness, is most pronounced.* 

No clearer elucidation could be devised of the pattern-principle in ques- 
tion than is furnished by the photographs of live Woodcock and Snipe (Figs. 
20-22 and 25-26). The imitation of the larger details of the squatting 
bird's near background is exquisitely perfect, particularly in Figs. 22 and 
25. Dead leaves, twigs, and grasses, variously disposed over shadow-holes, 
in a near view, are the main components of the pattern-pictures which 
such birds wear. Because they are strictly terrestrial and rather sedentary, 
in time of danger usually squatting motionless on the ground, and allowing 
enemies to approach them very closely before they fly, they are almost always 
seen against a comparatively near portion of the ground-plane, and hardly 
ever against a highly diversified forest landscape. Hence a picturing in 
slight reduction of the simpler ground-pattern of leaves and twigs, etc., com- 
mon to all the bogs and coverts which these birds inhabit, is all that is needed 
for the complete 'obliteration' of their counter-shaded bodies. 

Many other examples of this class of background-picturing could be cited, 
but the ones already given will sufiice. That most beautifully patterned bird, 
the European Woodcock (Scolopax rusticola), belongs in a distinctly different 
class, and will be considered later on. 

* These four pictures (Figs. 22-24B) are reproduced from the article in the Auk mentioned in 
our preface. 



34 




Fig. 25. Wilson's Snipe on its nest ; 'obliterated' by counter-shading and 

Sicture-pattern (representicig sticks, grasses, etc, with their shadows, at various 
i stances.) 

Photographed from life by Herbert K, Job. 
Here reproduced by courtesy of Houghton, Mifflin & Co. 




Fig. 26. Jack Snipe (GaUlnago caelestis.) Still more specialized 'picturing' of straight, bright sticks for 
dead reed stems, or broad grass-blades) and shadows, [Cf. the Chipmunk, Figs. 13 aud 93.] *'''=' *■ 

Photographed from life by Cherry and Richard Kearton. 
Courtesy aUo of CoBsell & Co. 




Fig. 27. Nesting Whip-poor-will. [Cf. Fig. 28.] 
Photographed from life by Herbert K. Job. 




Fi«. 28. Whip-poor-will (Antrostomus vocifervs) on its nest. Near-ground-'picturing' patterns of the minutest type, 
founded, as always, on obllterative shading. 

Photographed from life by Rett E. Olmetead. 



CHAPTER V 

BACKGROUND-PICTURING ON OBLITERATIVELY SHADED BIRDS, CONTINUED. 
SECOND TYPE, — INTENSELY ELABORATE PICTURING OF THE MINUTE 
DETAILS OF THE NEAR GROUND, ON TERRESTRIAL BIRDS 

THERE are two main types of intricate-pattern background-picturing, 
as there are two classes of minute forms and markings in field and 
forest landscape. The one consists of the actually minute markings of the 
various inanimate objects, such as leaves, logs, sticks, stones, grasses, etc., 
seen at very close range; and the other of the cruder forms of large objects and 
groups of objects, such as tree-trunks and branches, and sky-vistas, reduced 
and refined by distance into a delicate pattern. 

Marvelously fine and intricate patterns, rendering with almost microscopic 
minuteness the aspect of dead leaf and mossy log surfaces, seen at extremely 
close range, with an admixture of somewhat more distant ground-vista pictur- 
ing, are worn by such birds as the terrestrial forest Goatsuckers {CaprimidgidcB), 
which are almost- unique among birds in their evident extreme dependence 
on obliterative coloration. Squatting motionless on or near the ground in 
the depths of shady forests, they take wing only as a last resort, when almost 
trodden upon by an enemy. In conformity with this habit, their obliterative 
pattern is developed to a point of minutely detailed realism quite beyond 
that of such well-concealed ground birds even as the American Woodcock. 
It is as if the Woodcock wore an adequately true facsimile of the main effect 
of its dead leaf and stick background, with the smaller markings of these ob- 
jects largely omitted, while the Goatsucker wears a similar pattern-picture 
carried out to the last degree of finish, with all possible minute details faith- 
fully represented. The intricate bark- and lichen-pattern of the surface of a 
fallen log, the reticulations of dead leaves, — all the innumerable delicate mark- 

35 



ings discernible upon close scrutiny of the forest ground, together with the 
larger pattern formed by groups of slightly more distant leaves and twigs, etc., 
with their high-lights, their middle tones, and their dark shadows, — all these 
things, variously reduced by perspective, are clearly suggested to an appreci- 
ative observer by the marvelous patterns of the forest Caprimulgidcs. The 
fact that none of these detail-picturings is so patently realistic as to be appreci- 
able to everyone when the bird is seen away from its natural environment, is 
part of the very marvel of the thing. Thanks to some process * which in its 
visible results has amounted to something like an averaging of all the normal 
backgrounds, against which, from aboriginal times, the animals have been 
seen, they bear a pattern precisely similarto none, yet amply fitting all. This 
effect of perfect averaging or compounding is one of the most beautiful and es- 
sential parts of the obliterative principle. (In certain cases, which will be 
considered later on, an animal's background is subject to so little variation 
that a more simple and single imitation of absolute details is possible.) 

Though fully developed, the obliterative shading underlying this pattern- 
system of the goatsuckers is slight in range, conformably to the diffuseness 
of the top-light in deeply shaded woods, which these birds inhabit during 
the day. True obliterative coloration perhaps makes its nearest approach 
to mimicry among animals bearing this form of pattern. For while the coun- 
ter shading as well as the character of the markings proves the case to be one 
of obliteration, or merging with the background, yet the apparent extreme 
nearness of some of the pictured details, which in certain views will even ' co- 
alesce ' perfectly with the markings of the very object on which the animal is 
sitting, such as a stone or mossy log, gives the phenomenon, in part, close 
kinship with the exact mimicry of surface-detail on an animal whose protec- 
tion is the simulation, with full appearance of solidity, of a single inanimate 
object. It is furthermore undeniable that a finely-patterned bird such as we 
have been describing does occasionally pass for an excrescence of the log or 
rock on which it sits. This may be the case, for instance, when it is seen in 

* We ourselves attribute all such work to natural selection, pure and simple and omnipotent. 

36 




Fig. 29. Nighthawk— a perclier in the open, on lichen- 
freckled rocks, tree boughs, etc. Near-ground-pictnring of the 
minutest type (based, of course, on obliterative shading.) 

Photographed from life by J. E. Seebold. 




Fig. 30. Nesting Nighthawk. [C£ Fig. 29.] 
Photographed from life by Ora K. Knight. 




Fig. 31. Rnffed Grouse walTiing. 'Obliterated' by its higbly- 
wroiigbt picture-pattern, based on complete obliterative shading. 
Photographed from life by James R. Mill*^. 




Fig. 32. Nesting female Ruffed Grouse. 

Photographed from life by James R. Miller. 



full side-contour against an unfavorable background, especially if its mark- 
ings do not clearly show. For, we repeat, these markings, though pictures 
of comparatively near details, are still pictures, in the sense of representations 
of patterns beyond the animal, and not exact facsimiles of the surface-mark- 
ings of any object. It must be remembered that a large class of the enemies 
of such a bird, namely, the terrestrial carnivorous quadrupeds, which ap- 
proach it on its own level, usually see it against a more distant background 
than do we tall bipeds who look down upon it. In accordance with this fact, 
it will be found that there is more than one would at first suppose of the ele- 
ment of distant background picturing in the side-markings of most terrestrial 
birds. But even if it is merely the thickness of an animal's counter-shaded 
body which habitually intervenes between its exposed side and the seeming 
background pictured by its markings, the principle is not mimetic, according 
to our nomenclature. To complete the statement, we must add that no ani- 
mal bearing a full obliterative shading can, under normal conditions, pass for 
some other kind of solid object, but must appear either as a flat plane, or as 
merged into the scene behind it, whether near or far, — the smallest possible 
extent of its apparent retrocession being a distance corresponding to the thick- 
ness of its own body; but in order that it may completely undergo such 'ob- 
literation' the pattern which it wears must always be smaller than the actual 
pattern of its background. 

Figs. 27-30 need no explaining in the text. 



37 



CHAPTER VI 

BACKGROUND-PICTUEING ON COUNTER-SHADED BIRDS, CONTINUED. THIRD 
TYPE, — ^PICTURING OF THE MORE DISTANT BACKGROUND ON PARTIALLY 
ARBOREAL BIRDS 

IT is obvious that high-standing and tree-perching birds tend to have more 
distant 'backgrounds' than do those that squat on the ground, and that 
in many cases the only pattern which could adequately cooperate with their 
obliterative shading would be one which should 'coalesce' with a highly diver- 
sified forest-interior landscape. A landscape, that is, made up of tree trunks 
and branches, near and distant, the interminably various criss-cross pattern 
of the smaller twigs, stretches of sunlight-dappled ground, glimpses of sky, 
etc., — or, in other words, the second type of intricate pattern named in the 
preceding chapter. 

Such a pattern exists on many birds, and when, as in nearly all the cases, 
it is to some degree commingled with a representation of the nearer details of 
the ground-plane, to suit its wearer's partially terrestrial habits, it marks the 
very consummation of the obliterative principle. Certain forest grouse, 
such as the Bonasa umbellus or Ruffed Grouse of North America, and the 
Hazel Grouse {Bonasa hetulina), of Europe, are perfect examples of this type. 
The colored plate represents a cock Ruffed Grouse, against a variegated forest 
interior. This picture, as stated in the Preface, was painted from woodland 
photographs, etc., and from a stuffed grouse in a house-lighting artificially 
arranged to suit the bird's counter shading. Notice his complete lack of 
light-and-shade indicative of solidity — by which lack his beautiful ground- 
and-forest markings are enabled to 'coalesce' effectively with those of his back- 
ground. Such — or even more magically obscure — is the aspect of a live 
Ruffed Grouse in a naked tree, which the eye of the hunter scans in vain at- 

38 



BXPLANATIOM OF PLATE ;i 



MALE RUFFED GROUSE IN THE FOREST. 



Painted by Gerald H. Thayer 

¥"1 . 



PLATE II 




A HDET! He oo. >U«,1,?MnRE , 



tempt to detect its ghostly form. The bird is in plain sight, but invisible- 
such is the wonderful power of full obliterative coloration. Nature has, as 
it were, used the bird's visually unsubstantialized body as a canvas on which 
to paint a forest vista. In this there is nothing of mimicry, as we define it. 
Mimicry uses the solid aspect of an animal's body, modified in form and color, 
to simulate some other solid object. But vista- or background-picturing, 
based on the complete obliteration of the animal's solid aspect, which causes 
its actual form to pass for an empty space, is a widely different principle. 
Even in the terrestrial moments of the Ruffed Grouse's life, it is usually seen 
against more distant backgrounds than are the Goatsucker and Woodcock, 
because it largely lacks the squatting-habit, except in the case of the young, 
or the female sitting on her eggs. (See Figs. 31-33.) Noteworthy in this 
connection is the fact that the markings of the sexes are decidedly unlike. In 
the female, the most critical portion of whose life is probably the annual three 
weeks' brooding on her ground nest, the blotchy near-ground pattern pre- 
dominates over the forest- vista pattern; whereas in the male it is just the 
other way. It is difficult or impossible to distinguish the two styles of pattern 
absolutely in either case. But they are so adequately commingled, in one or 
the other predominance, that, however the bird is placed, some portion is 
almost certain to coalesce perfectly with its background; and with this key- 
note of complete obliteration the remainder of the pattern amply serves its 
purpose. Indeed, not even this degree of actual immediate 'matching' is 
necessary for the bird's concealment. His costume is a sort of patchwork of 
pictures, subtly intermingled, each an epitome of some particular type or 
detail of woodland scenery. Such details and bits of landscape are charac- 
teristic of the place in general, and even when those furnished by the grouse's 
pattern are unmatched by any in his immedjate background he is not apt to 
be revealed. Only an artist, perhaps, can rightly appreciate the profound 
and perfect realism of these background-pictures worn by birds and other 
animals. Just as a good caricature drawing of a man looks in one sense 
more like the man than the man himself, so, in a far more high and wonderful 

39 



degree, do these pictures on animals' coats exceed the verisimilitude of the 
actual scenes they imitate. They have been compounded and epitomized 
and clarified till only pure, essential typicality remains. The difference may 
be stated tersely thus : On the one hand, we see a stick, a leaf, a web of twigs 
over the sky; on the other hand, we see stick, leaf, web of twigs over sky. Just 
as in great human art, but far more essentially and surely, the trivialities 
and chance individual abnormalities have been eliminated, or subordinated 
to the scheme of ultimate, impartial typicality. To learn, then, the purely 
characteristic colors and light-and-shade effects of leaves and sticks and 
stones and other parts and types of natural scenery, we should look not at the 
scenes themselves, but at the animals whose patterns picture them. The 
essential realism of these pictures is such as the keenest artist among men 
could never hope to match. Nay, for Nature herself has made them — Nature 
herself has discovered and applied, to a point utterly beyond human emula- 
tion, the art of painting pictures. 

Let us recur once more to the Ruffed Grouse. The transverse barring 
of its breast and flanks, a form of marking common to a majority of the larger 
birds inhabiting northern forests, closely imitates the appearance of hori- 
zontal branches seen at rather short range. Such branches are a very im- 
portant feature of coniferous forest scenes. When this barring occurs on 
the underside of a forest bird, it is almost invariably continued by a series of 
spots on the outer webs of the primary wing-feathers. These spots become 
confluent when the wing is folded, and thus the large-branch-picturing is 
made to extend almost uninterruptedly across the bird. (See the colored 
plate. Our grouse, however, was rather weakly barred underneath.) The 
beautiful oval-spotted pattern of the Ruffed Grouse's rump is somewhat hard 
to analyze. It plays a small part in the side views, but has great prominence 
when the bird is seen from above. More than anything else, perhaps, it 
looks like a several yards distant patch of pine-needle-covered ground, peppered 
with small dead leaves, such as those of the Checkerberry (Gaultheria), or 
dappled with broken flecks of sunlight. 

40 




Fig. 33. Ruffed Grouse brooding. This 

picture admirabl y illustrates a phase of 
ground-matching by the Ruffed Grouse's 
most beautiful and elaborate 'obliterative' 
picture-patterns. 

Photographed from life by George C. Embody. 




Figs 34-35. Dead Ruffed Grouse laid on its side. Fig. a4, breast view; Fig. 35, back view both consnif-nn.i^ 
because in wrong po.sitions for the normal working of the obliterktive shading. ' conspicuous 

Photographed oxit of doors. 




Fig. 36. Two photographs of the same piece of a Croat Horned Owl's wing, super-Imposed on a photograph of white 
pine woods, to show how' lIdscIj- the owl's patterns reproduce such a forest-interior. 



It is to be remembered that aside from the nesting ordeal, the Ruffed 
Grouse's greatest need of protection is in the autumn and winter, when many 
of the trees are leafless. Deep wood interiors are more or less brown, even 
in summer, and, above the ground, in winter likewise, so that a grouse's colors 
are never really out of harmony with its environment; but it is in the two 
brown, leafless seasons between green summer and white winter that the 
average likeness between bird and landscape is the closest. During the 
snowy winter months the Ruffed Grouse becomes more largely arboreal, 
climbing about among the smaller branches of deciduous trees, with almost 
the agility of a parrot or crossbill, picking buds — ^which are its principal food 
at this season. Forest vistas above the ground, with the intricately striate 
pattern of small, naked twigs, are therefore among its commonest winter 
backgrounds, and a large element of its pattern fits these scenes to perfection. 

Another bird which wears a highly developed forest-vista pattern is the 
American Great Horned Owl (Bubo virginianus). This owl sits nearly 
erect in deep woods, and its obliterative shading is proportionately slight. 
Horizontal-branch-barrings are the chief pattern of its underside, while its 
back and particularly its wing-coverts bear a beautifully suggestive picturing 
of variously extended vistas through the twigs and tree trunks. (See Fig. 36.) 
The white breast-mark looks like a sky vista, or some other large, light-colored 
detail of the woodland scene. It belongs among. contour-breaking 'ruptive' 
markings (see Chapter XIII, pp. 77-78) and among those which 'let in' the 
sky (chapter XXII, p. 149, etc.). 

The great European Eagle Owl {Bubo maximus) is almost the counter- 
part of B. virginianus in coloration, but somewhat more boldly and sparsely 
marked, in accordance with its less strictly sylvan life. 

The Great Gray or Lapp Owl (Scoptiaptex cinereum and 5. cinereum lap- 
ponicum), an inhabitant of dense fir and spruce forests in the far north of both 
continents, wears a congested but little diversified pattern strongly suggestive 
of the dusky recesses of these northern woods. Most beautiful of all is the 
forest-picturing on the little Screech Owl (Megascops asio) of North America. 

41 



As is well known, there are two perfectly distinct color-phases of this owl, 
the red and the gray. It is in the gray plumage that the forest-pictures are 
most highly developed. Largely confined to this phase, also, is the curious 
defensive, habit of sitting sharply erect, raising the ear tufts straight upward, 
closing the eyes to narrow diagonal slits, and drawing the feathers so close 
to the body that the usually fluffy bird is reduced to about one third its ordinary 
thickness. Of this interesting performance only one explanation, and one 
which long seemed sufficient, has been forthcoming. People have supposed 
that the owl practices protective mimicry, by assuming the aspect of a stick or 
stub. While it is not to be doubted that such a purpose is often served, in 
part, at least, yet the fact that the bird has counter shading — which even in the 
nearly erect position tends to 'obliterate' it, and to make it look unlike a stick 
— together with the very evident forest-vista character of its pattern, goes far 
toward proving that mimicry is not the only object of the trick. The grotesque 
contraction serves also to bring the background-pictures to their clearest and 
sharpest. The more tightly and closely a bird's feathers are laid against its 
body, the clearer do all its markings become. The Ruffed Grouse has a like 
habit — so have bitterns and many other obliteratively colored birds — and 
in all these cases the action, whatever may be its other merits, is an essential 
adjunct of the obliterative equipment. Since, by every token, these birds 
are preeminently equipped for obliteration rather than for mimetic resemblance, 
it seems likely that the contracting-trick has greatest value as a factor of 
obliteration. On the other hand, it is undeniable that any such 'contracted' 
bird has moments of close mimetic likeness to a stick or stub. I shall return 
to this question in a later chapter. 

Judged by its markings, the European Woodcock {Scolopax rusticola) 
would seem to belong most decidedly to the 'forest-w5to-picturing' class, 
and such an opinion is largely vindicated by an examination of the bird's 
habits. It lives to a great extent in upland forest coverts, where its beautiful 
and intricate wing- and side-pattern matches the vistas among trees and 
stumps, with glimpses of mottled forest ground, while its barred breast matches 

42 




3?8 

-*^ 
o P* 

>-^ 

n f 
o o 



*fl P 1 

o S 5 




standing twigs and branches, and their shadows cast upon the ground. Many 
other -ieautiful examples could be given of this type of Jorestrpattern^among 
birds. 

The next chapter will treat of grass patterns, separated from the other 
forms of near-background pattern which have already been considered because 
of their involving slightly different principles. 



43 



CHAPTER VII 

BACKGROUND-PICTUiaNG ON COUNTER-SHADED BIRDS, CONTINUED. GRASS 
AND HEATHER PATTERNS ON SPARROWS AND GALLINACEOUS BIRDS, ETC. 

THE grass-pattern birds, of various orders, constitute a pretty clearly- 
defined group in the obliteratively-patterned series. Generally speak- 
ing, there is much less diversity in the backgrounds of terrestrial birds which 
live in the open, than in those of forest birds, whether terrestrial or arboreal. 
The ingredients of a field bird's background are comparatively few and 
simple, for the predominant vegetable forms of the open land are much less 
diverse in size, and somewhat less in shape, than those of the forest. Further- 
more, birds that are habitual dwellers on open ground — ^which, relatively to 
the littered forest floor, lacks minor variations of level — are rarely seen against 
anything but a very near background. Thus the possibility of their needing 
the distance-picturing type of obliterative pattern (as described at the be- 
ginning of Chapter VI) is largely eliminated. This comparative simplicity 
of marking requirements would lead us to expect great uniformity in the 
patterns of field birds; and investigation vindicates the supposition. Among 
the birds which are wholly confined to open ground, either bare or grass- 
grown, but which annually range over a wide territory, so that no one region's 
peculiar ground-forms could advantageously be pictured on them, there 
exists a highly conventionalized ground-pattern of a fixed type, which is re- 
markably little varied through several genera and families, even orders. 
This tj^e, always based on complete obliterative shading, is characterized 
by striations of light brown and black, coarsest on the back, and more or 
less varied by transverse bands and finer markings on the wings, scapular 
feathers, and other portions. Birds which wear it are Larks {Alavdidm) 

44 




Fig. 39. Rocky Mountain White-tailed Ptarmigan in transitional plumage, 
against snow-brindled ground. 

Photographed from life by Edward R. Warren. 




Fig. 40. Rocky Mountain White-tailed Ptarmigan on her nest. Neur-ground-picturing pattern, of the grass-type 'based, of 
course, on full oblitera/tive shading.) [Seep. 47, Chap. VII.] 

Photograpbed from life by Evan Lewis. 




Fig. 42. Hocky Mountain White-tailed Ptarmigan among pebbles, rocks and grasses. (Female and cliick.) [Cf. Figs. 39-41. J 

Photographed from life by Edward R. Warren. 




Fig. 43. Sage Gronse (Centi-ocercus uropha&ianiis) , a 'grass-patterned' 
and 'shadow -marked ' bird. 

Photographed fi-om life by Edward R. Warren. 



(almost all the species except the Shore Lark and its races), Pipits {Anthus), 
certain European Warblers (Sylviincs), various members of the FringilUdcz, 
and some of the shore and moorland haunting Limicolce, as the Curlews 
(Numenius), and other Waders. Some of the more sedentary and local of 
the migratory field birds, as for example, the North American Yellow-winged 
Sparrow {Ammodramus savannarum passerinus) and the European Quail 
(Coturnix communis), have developed more highly specialized patterns of a 
very subtle nature, — ^patterns beautifully suggestive of the intricate small forms 
of earth and grasses. But it is among the actually sedentary (i. e., non-migra- 
tory) ground-birds of mountain moors and pastures, monotonous and little- 
varied regions, where the forms of vegetable growth which cover the summer 
ground are very limited in number, that the most simply specialized of back- 
ground-pictures may be found. Such birds are the Ptarmigans (Lagopus), 
already mentioned as preeminent among special-pattern birds. Living 
always in exposed situations, and being much sought by many rapacious birds 
and mammals, they are peculiarly dependent on protective coloration, at 
all seasons. Almost all the species (the sole exception, as far as I know, 
is the Scotch "Grouse," Lagopus scoticus) turn white in winter, when their 
boreal or alpine haunts are covered deep in snow. In spring and fall the 
birds pass through a long intermediate stage, when they are curiously and 
ever-varyingly pied with white and brown or gray. The fact that they are 
thereby aided to escape detection on brown vernal ground mottled with 
patches of melting snow, or on ground half dimmed with scanty autumnal 
snowfalls, might be considered nothing more than a coincidence, were it 
not for the extraordinary slowness of the two seasonal color-changes. There 
is perhaps no other bird which moults as gradually as the Ptarmigan, and this 
fact goes very far to strengthen the supposition that it has developed a pecu- 
liarly fluid and perfect system of perennial protective coloration. Figs. 
8, 9, lo and 39 show White-tailed Ptarmigans, of the Rocky Mountains, in 
winter and transitional plumages. The photographs were taken from wild 
birds in their native haunts. Supremely beautiful and potent is the grass- 

45 



pattern of this same species in summer plumage. See Figs. 40 and 41, 
the second of which is one of the most remarkable photographs ever taken 
of obliteratively colored birds in nature. Both photographs are of hen birds 
on their nests. We have never been in the haunts of this ptarmigan, and 
therefore cannot speak from personal experience as to the prevalence on 
its breeding grounds of the strong, wiry grasses which form the brooding 
bird's background in these pictures, as well as in others not published here. 
But the late Mr. Evan Lewis, of Idaho Springs, Col., who took the photo- 
graphs, wrote us confirming our for.egone conclusions as to the abundance 
and general distribution of grasses of this type in the summer home of the 
Southern White-tailed Ptarmigan. Indeed, an examination of the photographs 
leaves one no room for doubt upon this score. So consummate a resemblance 
could not be merely casual. 

The principal feature of the pattern made by grasses over ground is a more 
or less intricate lace-work of crisscrossing, light-colored, linear forms, some 
straight, some curled and twisted, relieving with varying intensity against 
dark. This pattern has the important attribute of simplicity, and is worn not 
only by many birds and some frogs, but even by certain moths, which rest on 
the ground during the da)?time.* In the case of the ptarmigan, it is achieved 
by light-brown marginal bands, with a few small internal spots, on the dark 
feathers of the upper parts; the predominance of light and dark being grad- 
ually reversed as the lower breast is approached. The belly is entirely white, 
as are the quill feathers of the wings and tail. The white of both wings and 
tail, however, is entirely hidden by grass-marked 'coverts' when the bird is 
brooding. In addition to the phases already described, this bird has an 
early autumn plumage of softer and grayer colors, withotit white blotches, 
which doubtless fits it to live more among the rocks, and less among the 
grasses. The colors of ptarmigans, in fact, are almost interminably various, from 
month to month. It seems almost as if they underwent a perpetual moult. The 
grass-pattern plumage of the nesting season, however, must be very constant. 

* These will be considered later. 
46 



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Fig. 47, Nesting female Eider Duck. Ground-pi cturiag pattern, based on counter-shading. 

Photographed from nature. By courtesy of "Country Life," London. 




Fig. 48. Young Short-eared Owls, in their nest on the ground. 
Photographed from life by Cherry and Richard Kearton. 



Another kind of Ptarmigan of which we have secured good photographs 
from life is the Lagopus scoticus, the so-called "Grouse" of the British Isl- 
ands (Figs. 44 and 45). This is preeminently a bird of the heather, and it is 
gratifying to see how subtilely and significantly its markings differ from those 
of the American species which nest among grasses. It is completely covered 
with wonderful heather-pictures, recognizable as such even when the bird is 
examined away from its true environment. The more complex forms of the 
crowded and delicately branching heather plants, with their twigs and leaves 
and blossoms, are copied by various modifications of the bird's pattern. Rel- 
atively to that of the grass-ptarmigans this pattern is characterized by the 
multiplicity of its small, light-colored forms, which are also greatly more var- 
ied both in shade and color, to simulate the complexer surface-pattern and in- 
terior-vistas of the heather plants, with their variously illuminated details. 
(Technically, the difference consists chiefly in the wider and wavier marginal 
bands, and in a copious speckling of darker brown upon the fuscous ground- 
color within these bands.) The bird shown in Fig. 40 was unfavorably ar- 
ranged as to obliterative shading, but certain features of its obliterative pat- 
tern are shown off to consummate advantage. The pattern of its rump and 
back is scarcely recognizably different from that of the heather around its tail 
and nearer wing, while the picturing of heather-bells by its breast-pattern is 
astonishingly close. The obliterative shading of this species is so extremely 
slight that we must infer that it is wont to lie very deeply settled into the heath, 
and often more or less overarched by it, so that the preponderance of direct 
top-light is reduced to a minimum. The dark area on the actual belly, which 
this species shares with several other gallinaceous birds of different genera, 
has little or no bearing on the case, as it is invariably out of sight when the 
bird is "lying close." (The use of such markings will be discussed in a later 
chapter.) The ptarmigans which resort often to bare ground and rock, as 
also the arboreal Gallinse, lack this 'squatting-patch,' and light bellies are 
essential factors of their concealment. Even some of the rock-haunting 
ptarmigans, however, have a somewhat weak obliterative shading, and this is 

47 



in keeping with the fact that on mountains there is an unusually great pro- 
portion of side-light 

Still another notable type of pattern worn by birds of grass-lands and the 
open plains, is composed of a system of bold transverse bars of black and 
brown, or kindred colors. This exists, for instance, on some of the Tinamous 
(Tinamidts) of South America, and, in a very high state of development, on 
the European Great Bustard {Otis tarda). Its effect is much the same as 
that of the other grass-patterns, but it seems in most cases to be a cruder and 
less highly finished form. The pattern of the Little Bustard (Otis tetrax) is 
somewhat of this type, though refined toward elaborate picturing, and is very 
beautiful and effective. The female especially is one of the most exquisitely 
counter-shaded and picture-patterned of birds. 



48 




Fi«. 49. Yellow 
Wagtail amid 
grasses. 

Photographed from 
life by Cherry and 
Richard Keartou. 



Fig. 50. Male Bob-white 
(Colinus virginiariiis) on its 
nest. Highly-developed pic- 
ture-pattern, based on full 
obliterative shading. 

Photographed from life by 
Maimfielf S. Crosby. Courtesy of 
"Bird Lore." 





Fig. 51. Male Golden Plover with chick, in grass. Obliterative shading and grass-pictiiring-pattern, etc. This 
bird is also a heather-haunter. [See p. o3, Ghap, IX.] 

Photogmphed from life by Cherry and Richard Keartoa. 




Fig. 52. Nesting " Upland Plover" (Bartram's Sandpiper), a 'grass-patteru' bird. 
Photographed from life by J. E. Seebold. 



CHAPTER VIII 

BACKGROUND-PICTTIRING ON OBLITERATIVELY-SHADED BIRDS, CONTINUED. 
THE VARIOUS PATTERNS OF SCANSORIAL BIRDS 

SCANSORIAL birds are for the most part tree-trunk climbers. They are 
the Woodpeckers {Picida), the Wrynecks {Jyngida), the Nuthatches 
(Sittince), the small Northern Creepers (Certhiidcs), the Wood Creepers 
(Dendrocolaptidce), and a few other forms. 

Most of these birds — notably both families of Creepers — spend almost 
all their time in a nearly vertical position, clinging to the bark of tree trunks 
with claws and tail, or claws alone. The Nuthatches climb head-first down- 
ward as well as upward, the others seldom or never do. 

In spite of the erect climbing-position in which they spend their lives, 
these birds are almost without exception dark on the back and light on the 
breast and belly, and many of them have a delicate, complete gradation from 
the dark side to the light. The underside may be pure white, as in the case 
of many woodpeckers, or brown, barely lighter than that of the back, as in 
some of the DendrocolaptidoR. But in the whole catalogue of species we 
know of none which is not thus counter-shaded, more or less pronouncedly. 
But how, then, the reader may ask, does this regulation counter shading con- 
form with these birds' vertical habit of life? The answer is plain. The solid, 
leaf-crowned trunks up which they climb cut oflf the light from their breasts, 
and almost all that reaches them strikes laterally or diagonally on their backs. 
It is the same scheme over again, but carried out on a vertical instead of a 
horizontal plane. 

The patterns of these climbing birds are extremely various, ranging from 
none at all, as in some of the Wood Creepers, etc., to exquisitely elaborate 

49 



bark- and vista-pictures much like those worn by goatsuckers, as in the Wry- 
necks. 

The unmarked Wood Creepers — ^whose counter shading also, in some 
cases, is very slight — ^frequent brown stumps and trunks, in very heavily 
shaded forests. Other members of the same family, with closely similar 
habits, have streaks and a more pronounced counter shading. 

Bark picturing plays a very large part in the disguises of several classes 
of animals, probably reaching its consummation among moths and butter- 
flies, as we shall see later on. Cruder * forms of it among birds are represented 
by the streakings and mottlings of the Creepers (Certhiidce and Dendrocolap- 
tidoE), by the close transverse barrings of the backs of certain Woodpeckers, 
and the bold spottings and stripings of other members of that family. AH 
these devices, especially the barrings and stripings, are, at a little distance, 
effective bark-pictures. The pattern of the small Northern Creepers {Cer- 
thia) is perhaps too highly developed to be rightly classed among these others, 
and should be treated rather as a connecting link between them and the ex- 
quisite picture-pattern of the Common Wryneck (Jynx torquilla). This last 
is one of the mpst wonderfully equipped and beautiful among obliteratively- 
colored birds, and is evidently one which, like the goatsuckers, often stays 
stock-still in time of danger, allowing its enemy to make an exceedingly near 
approach before it moves. Its buff-colored breast and rufous primaries bear 
the same form of transverse dusky barring as is worn by so many of the larger 
forest birds, while its back is mottled and lined and peppered with several 
tones of gray and dusky, in minute picturing of bark seen at close range. In 
back view the bird would usually be seen against the very tree to which it is 
clinging, in side view usually against branches and trunks, and more distant 
forest vistas. And behold! its markings are developed correspondingly. 

* Whenever we call a coloration cruder, or less developed, without trying to state the function 
of this so-called crudeness, it must be understood that such a function surely exists. It is, evidently, 
only the need of this coloration to represent different backgrounds, that can limit its development 
toward any particular one. — A. H. T. 

50 



On its sides (breast, cheeks, flanks, wing-coverts, etc.) are the delicate twig- 
and vista-pictures, and on its back the near-bark marblings. The beautifully 
banded tail serves well in either view. Indeed, the Wryneck's oblitera- 
tive coloration involves the same principles and sorts of background pictur- 
ing as does that of the Ruffed Grouse and other forest birds described in 
Chapter VI. 

We have now glanced at most of the main types of coloration among tree- 
trunk-climbing birds. In a later chapter I shall recur briefly to the subject 
of the bolder markings of woodpeckers and nuthatches. 



SI 



CHAPTER IX 

BACKGROUND-PICTTIRING ON OBLITEEATIVELY-SHADED BIRDS, CONTINUED. 
BEACH-SAND- AND PEBBLE-PATTEENS OF THE SHORE BIRDS (LimicolcB). 
GENERALIZATIONS AND COMPARISONS 

OBLITERATIVE shading, pure and simple, is the rule among the Shore 
Birds (Limicolce). There are a few somewhat anomalous cases — 
e. g., the summer costumes of the Golden and Black-bellied Plovers, and the 
Dusky Redshank (Totanus juliginosus), which we will consider later on; 
but for the most part the birds of this order show great simplicity and uniform- 
ity in their obliterative coloration. The markings of many of the species 
which inhabit pebbly shores and wave-marked, sandy beaches are much like 
those of the grass-pattern birds described in Chapter VII, but even simpler. 

Littoral flats, whether of sand or shingle, are for the most part characterized 
by great monotony and blankness, being governed by few and simple laws, 
and almost wholly wanting the complex element of vegetable life, with which 
we have had mainly to deal in the foregoing chapters. Since the birds that 
inhabit these beaches are almost all great wanderers, making long semi- 
annual migrations, one would expect to find their patterns not only simple 
but highly generalized, and varying little among the species. A comparison 
of the more strictly littoral among the smaller shore birds will show that this is 
actually the case. There are,, indeed, two quite distinct types among them, 
but almost all the species belong to one or the other of these two. The one 
includes those which are largely destitute of picture-pattern — e. g., the smaller 
plovers {Mgialitis), the other those which are well provided with such pat- 
terns, of a regular and simple kind — e. g., many of the sandpipers (Tringa, 
etc.). The patterns of sand and shingle and tidal mud flat are apt to be so 
slight that a bird can be well concealed on such ground by counter shading 

52 



and color alone, as in the case of the plovers; but Nature has given many of 
her beach-birds a picturing of the faint patterns. Wave-lines left at low 
tide on bright sandy beaches, narrowed in perspective, the lines of small 
lapping rollers over shallows, strips of stranded driftweed, shells, heaped or 
scattered, straggling blades of beach grass — these, varied by the even speck- 
ling of broad pebble-beds, are the chief features of the ground-scene on blank 
shores where sandpipers and plovers troop and feed. So do we find the 
bird's pattern, wherever it occurs, delicate and linear and wavy, with few in- 
tricacies, and a persistent tendency toward lengthwise striping and crescentic 
spots. The effect may be produced by light markings on dark, by dark 
on light, or by both; but the patterns are all much alike in general character. 
Marginal bands play the chief part in all these simpler picture-patterns, and 
this is even truer of the beach than of the grass type. These two phases of pat- 
tern are well connected by intermediate forms, worn by some of the LimicolcR 
that live more or less largely in the fields or moorlands. Such are the Cur- 
lews (Numenius), already mentioned among grass-pattern birds, the Thick- 
knees (CEdicnemidcE), and the North American Bartram's Sandpiper (Bar- 
tramia longicauda), which has, indeed, one of the most highly specialized of 
'grass-patterns.' (See Fig. 52 and Chapter VII.) 

Again, among the true plovers we find an outcropping of the heather pat- 
tern, in conformity with the heatli- and tundra-haunting habits of the birds 
that wear it. Such are the several races of the Golden Plover (Charadrius), 
which breeds in the far north of both continents, and, to some extent, its rel- 
ative the Black-bellied Plover (Sqtiatarola), of like distribution. 

Good examples of the pure beach t5^e are the winter costumes of the 
Knot (Tringa canutus), the Sanderling (Calidris arenaria), the Semipalmated 
Sandpiper (Ereunetes), and the Stints (Tringa minuta, T. temminckii, etc.). 
Most of the birds of this family wear a more grass-like pattern in summer 
than in winter, a fact which is in perfect keeping with their habits, for during 
the nesting season they tend to forsake the beaches and to live among 
the weeds and grasses. Some, like the Pectoral Sandpiper {Tringa 

53 



maculata), stick to grassy swamps throughout the year, and their pattern 
tells the tale. 

The true snipes (Gallmago), already treated of in another division because 
of the rich intricacy of their markings, have a pronounced element of grass- 
pattern, and both in markings and in habits form a connecting link between 
the grass birds and the woodland bog birds, typified by the American Wood- 
cock (Philohela minor). In like manner the sand- and pebble-type of pattern 
is modified toward rock-surface picturing, — as in the winter plumage of the 
Purple Sandpiper (Tringa maritima), one of the most highly 'obliterated' 
of birds, and a sandpiper peculiar in its restriction (at least in winter) to rock- 
haund ocean shores. In the same way the pattern of the terrestrial goat- 
suckers, described in Chapter V, is modified toward rock-picturing in the 
plumage of that rock-haunting member of the family, the Nighthawk (Chor- 
deiles). 

From all this it appears that the t5^es and forms of picture-pattern worn 
by birds, though easily separable into classes when grouped about the several 
conspicuously pure examples, are yet in the whole range of species closely 
blended and intermingled, more or less irrespective of the structural affinities 
of the birds which wear them, but nearly always in obvious conformity with 
their specific habits. It would seem, indeed, as if Nature in its entirety 
should represent one great, blended scale, shaded throughout insensibly like 
the colors in the spectrum, and as if the breaks and interruptions which form 
the bases of zoological classification and separate grouping were in a sense 
imperfections. In the world of birds, for instance, though the breaks and 
anomalies are numerous, there are yet many evidences of the past existence of 
a smooth gradation connecting tj^es now sundered.* On the other hand, it 
is also true that gaps in the fundamental affinities of birds are often super- 
ficially bridged over by similar habits, probably of more recent acquirement, 
and these are usually accompanied by corresponding outward resemblances, 

* See Robert Ridgeway, in the preface to his "Birds of North America," whence much of this 
thought is taken. 

54 



particularly those of plumage. Thus we discover, even in the study of the 
disguising-coloration of the birds of to-day, a wonderful intermingling and 
gradation between the types, which makes it hard to consider them separately. 
But division and classification are essential to analysis, and by taking a prom- 
inent type-center as the theme of a chapter, we can better examine both its 
differences and its affinities. Those we have already glanced at are perhaps 
the most representative and notable of the many types of picture-pattern worn 
by obliteratively-shaded land and beach birds. It remains for us to consider 
the markings of rails and other swamp birds, of obliteratively-shaded ducks, 
etc., and also the several obliterative uses more or less independent of counter 
shading which are served by spots and patterns in birds' costumes. 



55 



CHAPTER X 

BACKGROUND-PICTURING ON OBLITERATIVELY SHADED BIRDS, CONTINUED. 
REED PATTERNS AND OTHER MARKINGS OF BITTERNS. THE COLORATION 
OF HERONS IN GENERAL 

ONE more pronounced modification of the ' dead-grass ' type of picture- 
pattern must be considered. This is the picturing in a near view of 
straight, erect reeds, which exists on the necks and heads of several herons, 
notably the American Bittern (Botaurus lentiginosus), which shall serve as our 
example. Many herons are wont to stand motionless, with neck and head 
extended and erect, and in the bitterns this habit reaches its climax. The 
American Bittern will stand for an hour at a time in a swampy meadow, with 
scarcely a movement of its erected, straight and stick-like neck and head, 
terminating in the long, sharp bill, which points directly upward. When, as 
is pretty frequently the case, the neck and head in this position project above 
the reeds or grasses, they look, in certain lights, and from a sufficient distance, 
like a pointed stick or stub. This fact has been commented on by many 
writers, all of whom, it seems, have thought it a sufficient explanation of the 
Bittern's curious trick. Though we admit that the stick-aspect is sometimes 
most pronounced, and must therefore have a bearing on the significance of 
the habit, we are convinced that this has another function of far greater im- 
portance, namely, the display in correct position, and with the clearness 
gained by depressed feathers, of the reed-stripes on the upper neck, which 
extend sharp and unbroken over the head, and are even continued on the 
bill. The following extract from my journal, recording my first recognition 
of the high obliterative efficacy of these stripes, contains some details which 
make it worth quoting: "But if this [stick-mimicry] were the explanation, 
what would be the function of the finely developed, sharply contrasted stripes 

56 



of light and dark, running lengthwise of the head and neck, and best shown 
when the bird is standing erect in the attitude alluded to, with feathers closely- 
depressed? It is plain that these markings cannot help the 'stick' aspect, 
but must rather injure it, inasmuch as a single stick or stem would be of uni- 
form coloration, or at most mottled, rather than marked with sharp and strong 
longitudinal stripes. The true explanation flashed into my mind to-day as 
I was watching a standing Bittern at a distance of about ten feet. The light 
stripes on the bill were repeated and continued by the light stripes on the 
sides of the head and neck, and together they imitated very closely the look of 
separate, bright reed-stems; while the dark stripes pictured reeds in shadow, 
or the shadowed interstices between the stems. The truth of this explanation 
must be apparent to any one with an eye for such things, who watches at 
close range a Bittern standing motionless among reeds." To be sure. Bit- 
terns' heads and necks are often seen projecting stick-like over the tops of 
meadow-grasses and half-grown reeds, but who knows how many times Bit- 
terns' heads in this same attitude among the reeds escape all notice, by virtue 
of their beautiful rush-pattern? It may very well be that the projecting-stick 
aspect is, relatively at least, exceptional and unimportant. My own obser- 
vations of Bitterns in their haunts all tend toward such a conclusion. 

Reed-like patterns occur also, though in less marked development, on the 
necks of some of the true herons, as for instance the Purple Heron {Ardea 
■purpurea) of southern Europe. The beautiful European Bittern (Botaurus 
stellaris) has kindred markings with a strong admixture of richly brindled 
grass-pattern — a pattern at once bold and subtile, whose obliterative efiEect 
in the bird's normal environment must be consummate. So also with the 
South American Botaurus pinnatus. The Least Bitterns (Ardetia), of Eu- 
rope and America, have also delicately reed-marked heads and necks. There 
are doubtless many other examples which might be cited, but these are all 
that occur to me. 

A modification of the type of grass-pattern described at the end of Chap- 
ter VII occurs on the South American Tiger Herons (Tigrisoma), with their 

57 



minute transverse barrings or grizzlings of olive and black. Like the bit- 
terns, they are inhabitants of reed and grass swamps. All these birds have 
obliteratively-shaded bodies, and — in the slight degree consistent with the 
characteristic nearly erect position of these parts — obliteratively-shaded necks 
and heads. 

The coloration of herons in. general is exceptionally various, including as 
it does such extremes as the richly mottled brown of bitterns and the immacu- 
late snow-white of egrets and some others, — the supposed "conspicuous" 
species. (In a later chapter we shall show that these egrets too, and all such 
birds, are obliteratively colored.) Herons walk and rest, very commonly, 
almost erect, and their obliterative shading is often not very pronounced, 
though present, and evenly developed, in the majority of species. The colors 
of shallow and shaded water — subdued blues and greens and purples, some- 
times enriched and subtilized by iridescence,* predominate in their plumage, 
and they usually have bright reed- and water-colors on their naked legs and 
bills.f Their markings are various, sometimes pronounced and clear, some- 
times obscure, or even lacking altogether, but almost always perfectly and 
obviously consistent with the water-picturing suggested by their general color- 
tones. It is significant, too, that in spite of the much diversity in herons' 
colors, there are no brown and elaborately-patterned species except some of 
those that live in grassy marshes and dense reed-swamps, where they skulk 
almost like rails — the first subjects of our next chapter. 

* See p. 92, Chapter XVI. 
t See Chapter XV. 



58 





Fig, 53. ■ -rfoierican Bittern on its nest, 'obliterated' by picturo- 
patterii based on counter-shading. (The 'reed-stripes' mentioned in 
the text are here not in full operation. ^ 

Photogfrapbed from life by E. G. Tabor. 



Fig. 54. Nesting Virginia Rail, 'obliterated' by counter-shading 
and background-picturing pattern. 

Photographed from life by E. i>. Tabor, 




Fig. 55. TVilson's Tern on its nest. (Counter-shading and) 'ruptive' pattern. 
Photo^aphed from life by Francis H. Herrick. Courtesy also of G. P. PutDam's Sons. 




-! o< CCl, BAUIMOIIB . 



EXPLANATION OF PLATE HI 



MALE WOOD DUCK ON SHALLOW WATER. 

Sketch by Richard S. Meryman 



MALE WOOD DUCK IN A FOREST POOL. 

pointed by Abbo.tt H. Thayer, asslited by Richard 5. Meryman 

The bifd wag painted from a stuflfed specimen, and the 
Bkckgliound copied, color-note for color-note, .from the bird 
himgelf. Cf. the backgrotmds of the Ra.ttleBnake, Figtire 
128; the Bird-of-Paradise, Plate VI; and the Flamingoee. 



CHAPTER XI 

BACKGROUND-PICTURING ON OBLITERATIVELY SHADED BIRDS, CONTINUED. 
WATER MARKINGS AND COLORS 

THE duskiness of obliterative shading on such birds as rails, gallinules 
and coots, is in keeping with their habit of skulking under deep marshy 
cover, closely shaded from the direct top light, and often, momentarily, lighted 
more from the side than from above. A true obliterative shading exists, how- 
ever, on almost all the species. Two or three main types of coloration prevail 
among them, but there is little variation beyond these t3^es, and only such 
as is consistent with 'obliteration.' The colors of water, much like those 
worn by herons, predominate among the more aquatic species, the coots and 
gallinules. Olive, green, blue, purple, slate-gray, dusky — these are charac- 
teristic gallinule colors, and likewise the colors of water. A few of the birds 
that wear them are scantily or not at all counter-shaded. The Purple Galli- 
nule (Jonornis martinica) for instance, with its bright but softly-blended water 
tones, is as dark beneath as above, though there is a counter shading from 
the middle of its back to the lower edge of its folded wing. It lives for the 
most part over deeply and diversely shaded pools, and amidst the big, glisten- 
ing leaves of water plants, and its peculiar coloration does certainly achieve 
adequate 'obliteration.' (This will be explained more fully in a later chap- 
ter.) It is noteworthy, however, that in almost all cases where the adult 
plumage of one of these swamp-haunting species lacks obliterative shading, 
that of the young possesses it in full. This is true not only of the Purple Gal- 
linule, but in a remarkable degree of some of the jacanas, as the common 
Jacana jacana of South America. These birds live in tame and noisy flocks 

59 



on shallow lakes, lagoons, and miry marshes, and, unlike rails and gallinules, 
they do not skulk and stick to cover, but stay almost always in the open reaches, 
where they are exposed to the view of predatory birds and beasts. The adults 
are black underneath and rich red-brown above, with pea-green wings. As 
birds go, they are apt to be conspicuous, although not always easily discerni- 
ble amidst the multitudinous sharp lights and shadows of the lab)Tinths of 
lily pads over which they often walk. Watching a flock of jacanas feeding un- 
der the noonday sun, one sees from a little distance mainly the black-breasted 
adults — of the more daintily-colored, white-breasted young there seem to be only 
two or three in the whole flock of a score or more. But when the horizontal 
sun-rays of late afternoon or early morning stream across the marsh, behold a 
revelation! The young, concealed till now by their counter shading, show up 
in quantities, outnumbering the adults almost two to one. This is a most 
beautiful and convincing exhibition of the power of obliterative shading, and 
one which must leave a lasting impression on the mind of every observant person 
who sees it. But it suggests also an interesting question — so interesting that, 
though it leads us into the tabooed region of h)^othesis, we must be permitted 
to discuss it briefly. Why are the adult jacanas deprived of the counter shad- 
ing which served their youth so well? Adult gallinules also, it is true, lack 
counter shading, but they are always alert to skip into deep cover at a moment's 
notice, whereas the jacanas, as I have said, live in flocks, conspicuously ex- 
posed, in the open tracts of lagoons and marshes, and rarely or never take to 
cover unless wounded. Is it not highly probable that the strong spurs on 
their wings have something to do with all this? May it not be that the 
young, weak-spurred and inexperienced, need concealment in situations where 
the adults, with their hard, sharp thorns, are well able to protect them- 
selves?* Undoubtedly, the dark-hued parents must often serve to distract 
the attention of predatory creatures from their obliteratively-colored but 
defenseless young. Certain it is that these spurs are not, like those of cocks 

* There must, of course, be situations where the adults are as obliteratively colored as the young. — 
A. H. T. 

60 



and pheasants, for battles among the birds themselves, for they are worn 
equally by the small males and the much larger females. Evidently, then, 
they are for defense against outside enemies, such as alligators, iguanas, tor- 
toises, and predatory birds and mammals. That they are very effective 
weapons seems to be attested by the birds' abundance, noisiness, and tame 
and nonchalant manner. 

The colors of rails differ from those of gallinules and coots (and differ 
even among the several species), exactly as do their habits. They are more 
terrestrial, and their general color-scheme accordingly is browner. The 
backs of many species bear a subdued and dusky striate pattern of the 'grass' 
type — richer and brighter on the more terrestrial kinds, and vice versa. (See 
Fig. 52.) Some are slate-gray underneath, others pale rufous, or grayish 
white; but almost all have a complete counter shading, with a light culmi- 
nation on the vent and belly. Some, like the Yellow Rail (Porzana novebor- 
acensis), have a background-picturing pattern of delicate, grasslike, pale- 
brown barrings. But it is the patterns for which the birds of this family are 
peculiar that we have here to consider. These are the characteristic bar- 
rings on the flank feathers (in Rallus) and the system of pure-white specklings 
and slender stripings on the dark-colored upper sides (in Porzana) — mark- 
ings which, although not, indeed, strictly limited to the rails, yet reach an 
unusually high degree of development and significance among them. Water 
pictures of some kind they plainly are; and it is not difficult to go further and 
perceive what details and aspects of reed-swamp surfaces they most resemble. 
The white punctations picture broken glints of sky-shine on the dusky water, 
seen beyond and through the dim vegetation-pattern, rendered by the darker 
markings of the birds' backs. The barred flank-pattern pictures glimmering 
water intersected by bold shadows from the reeds — or by intervening shaded 
reeds themselves. That crane-like relative of the rails, the Courlan (Ara- 
mus),.th.e ground-color of whose costume is the deep, dull brown of heavily 
shaded, muddy water, has likewise a water-glint pattern of pure-white spots 
on its head and neck. This I have seen performing admirably its 'obliter- 

61 



ative' function, on a wounded bird in hiding. The white speckhngs of some 
of the Wood Sandpipers (Totanus) and various other water-haunting birds 
(e. g., the loons, Gavia) belong more or less strictly to this same class of 
'water-glint' pictures. 

So, too, the rails' barred flank-pattern has affinities with the markings of 
other water birds, such as certain ducks. On them, however, it is developed 
into ripple-picturing. The beautifully contrasted black-and-white bars on 
the flanks of the Wood Duck {Aix sponsa) are ripple pictures, and as potent, 
in their place, as the most elaborate markings of land birds — while they are 
even more remarkable in that they depict motion. These markings of the Wood 
Duck cross the flank feathers transversely, yet when the feathers are laid 
in their natural upcurled position, overlapping the wing, their pattern forms 
one brilliantly accentuated horizontal stripe. Thus, though made by flank 
feathers, this marking is merely another form of the longitudinally striate 
scapular- or wing-pattern worn by so many other ducks, and serves ex- 
actly the same purpose. More than two thirds of the American and 
European ducks have one form or another of this marking, and on many of 
them it is most pronounced. It corresponds to the 'secant' stripe of certain 
land birds, but is often more elaborate (consisting sometimes of several tiers 
of stripes), and has an even more definite 'obliterative' use. It may be seen 
in its perfection on the Wood Duck, already mentioned, on the Pintail (Dafila 
acuta), the Green-winged Teals (Nettion), the Garganey {Querquedula circia), 
the Widgeons (Mareca), the Golden-eyes {Clangula clangula, etc.), the Long- 
tailed Duck or Old Squaw (Harelda hyemalis), the Steller's Eider (Eniconetta 
stelleri), the Hooded Merganser {Lophodytes cucullatus), and the Red-breasted 
Merganser {Merganser serrator). Its position varies from the flank feathers, 
as in Aix, to the secondary wing feathers, as in Merganser, the tertiaries, as 
in Mareca, and the scapulars, the feathers of the sides of the back, as in Dafila, 
Nettion, Harelda — in fact, the great majority of species. Its character and 
effect, however, are nearly the same in these several positions. A swimming 
duck leaves a spreading, wedge-shaped trail of curling ripples, very noticeable 

62 



in quiet water, while shorter ripple-lines also roll out in front of the bird's 
breast. Seen in profile against the water, the duck's body hides a portion of 
the perturbed and wavy surface extending from its further side, and tends to 
'relieve' noticeably against it. But this 'relieving' Nature combats with the 
bright 'secant' stripes, which, by their beautiful likeness to rolling wavelets, 
with shine and shadow, go far toward 'merging' the duck's otherwise well 
'obliterated' body into the troubled water beyond it. The peculiar ripples, 
real and pictured, may still suggest a swimming bird, but just where the bird 
really is — where alone the eye is led to expect it — there seems to be nothing, 
but water, — ^for the wave-lines extend across its dim body. This is a very 
important factor of disguise among ducks, particularly those that inhabit 
quiet inland water. Among deep-sea ducks it is less common. But the 
same system, sometimes elaborated, and including sharp transverse markings, 
occurs on a few of the oceanic species. 

Another peculiar form of pattern, common to even more kinds of duck, 
is a fine, black or gray vermiculation of the back or sides, as on Teals, Scaups, 
Canvasbacks, Wood Ducks, and many others. Indeed, this pattern is al- 
most universal among ducks, and there are comparatively few (these mostly 
deep-sea kinds) that lack all trace of it. It serves as a generalized picturing 
of shimmering water, fretted with broken shore-reflections, or ruffled into tiny 
ripples by light breezes. Considering its prevalence among highly 'obliter- 
ated' water birds, one can hardly doubt that such is its main function. On 
some species which frequent shallow inland waters, like the Wood Duck and 
the Hooded Merganser, the dusky vermiculation is exceedingly close and 
delicate, over a ground-color of golden brown. In these cases it seems to 
picture the sandy bottom seen through shallow water at the stream's or 
pond's edge. As a rule, the vermiculated pattern occurs on the sides, and 
its minuteness therefore fits it to match its wearer's more or less distant 
watery background, with its ripples and reflections dwarfed and refined 
by perspective. The much coarser wavy markings of some geese, though 
they serve also the purpose of ground-, and grass-picturing, in conformity 

63 



with the birds' half-terrestrial habits, have yet much in common with ducks' 
grizzled water-patterns; and the two types are connectal by intermediate 
forms, e. g., the breast-pattern of the Ruddy Duck {Erismatura jamaicensis). 

Ducks have still another very characteristic obliterative marking, the 
bright-colored "speculum" — & broad band, often of metallic green, blue, and 
purple, crossing the middles of the secondary wing feathers. This marking 
can but poorly serve the purpose (commonly supposed to be the main function 
of all such marks) of display 4n flight, for the color is confined to the tops 
of the outer webs of the wing feathers, and so only makes a continuous band 
when the wing is folded. Its obliterative use, on the other hand, is most 
pronounced. It gives the effect of a 'window' through the body of the bird 
to the water or vegetation beyond.^f This speculum is almost always of some 
characteristic water tint — ^blue, green, or gray. Often it is highly iridescent, 
which makes it additionally effective (as will be explained at length in a later 
chapter). On some species, such as the Scaups (Aythya marila, etc.), it is 
white. But even pure white serves the same 'obliterative' purpose, picturing 
a sky-reflection on the background-water. 

All these factors in the disguising costumes of ducks are usually parts of 
an 'obliterative' scheme based on full obliterative shading. Very few ducks 
lack this counter shading, and most of them have it in full development, 
particularly the females, and the males in post-nuptial summer plumage. 
The singular change to a dull-colored summer dress, like that of the females, 
which most male ducks yearly undergo, is coincident with their loss, and lack, 
for many weeks, of all flight-feathers. Discussing this phenomenon, an 
eminent English ornithologist remarks: J "Most of these birds {Anatidce) 

* Much the same purpose is served by the beautiful metallic spots or patches of water-color 
(deep blue, green, and violet) on other parts of the body, worn by many sea ducks, notably Steller's 
Eider. This bird has indeed a supremely beautiful pattern of ice and water pictures. 

t Little used while the duck is swimming, but greatly when he walks about on the adjacent shore, 
in far greater danger from his enemies. These speculums prove, also, to have a wonderful power to 
obliterate their wearers against the sky, to the eyes of creeping enemies that flush them. — A. H. T. 

X See the "Encyclopedia Britannica," vol. iii, p. 776 (of the R. S. Peale Reprint). 

64 



shed their quill-feathers all at once, and become absolutely incapable of 
flight for a season, during which they generally seek the shelter of thick aquatic 
herbage, and it is further to be particularly remarked that the males of two 
sections of the family {Anatina and FuligulincB) at the same time lose the 
brilliantly-colored plumage which commonly distinguishes them, and 'go into 
eclipse,' as Waterton happily said, putting on for several weeks a dingy 
garb much resembling that of th^ other sex, to resume their gay attire only 
when, their new quills being grown, it can be safely flaunted in the open air." 
Here are the facts, but without the true conclusion which' should be drawn 
from ttem — ^the conclusion which is unavoidable in the light of a wider 
knowledge of protective coloration. This is, that the male duck's assumption 
of dull plumage is an adaptation to his new environment, rather than to his 
altered bodily condition. He skulks among the reeds because he is flightless, 
and he assumes a mottled grass- and reed-like pattern to fit him to this new 
environment; but the mottled pattern is no more protective, i. e., 'obliterative,' 
than the pied wa/er-pattern of his full plumage, worn when he forsakes the 
shelter of the shore. Male Eiders (Somateria) keep out at sea while their 
brown, mottled females (see Fig. 47) hatch the eggs (sometimes a long way 
from the water) and tend the young, and though the males (as well as the 
females) are flightless for a while, they retain their full plumage almost un- 
altered. This full plumage has no obliterative shade-gradation, but con- 
sists of a bold 'ruptive' pattern of ice- and water-colors— as will be further 
explained in a later chapter. A few male sea-ducks, such as the more or 
less wholly black Scoters (Oidemia), are conspicuous at sea, though well 
equipped for inconspicuousness against dark cliffs. Their females, which 
have to brood the eggs on shore, are more or less adequately ' obliterated ' 
by counter shading, color, and markings. There are, however, some species 
of swimming birds in which even the females are quite without counter 
shading. Such are swans,* for instance, and cormorants — though cormo- 
rants are otherwise equipped for concealment on shore by rock-like 

* See p. 154, Chapter XXII. 
65 



markings, and by iridescence, which must often admirably mask them under 
water also. 

The foregoing sketch of ducks' disguising coloration touches on most 
of the main general facts. But the reader must liow be subjected to a de- 
tailed description of the obliterative equipment of one particular species, the 
Wood Duck, the male of which is almost unsurpassed among birds in the 
combined boldness and intense subtlety of its disguising coloration. (See 
Plates III and IV.) The general scheme of this beautiful bird's 'disguise- 
ment' includes a full and potent obliterative shading, from blue-black on 
the back and tail to pure white on the entire underside, shading through 
sand-color on the flanks and through chestnut, mixed with white, on the 
breast. The throat also is white, ending abruptly against deep velvet bronze 
and purple on the cheeks. Founded on this, underlying obliterative shading, 
which cancels the bird's visible solidity, and prepares him for 'background 
matching,' there is a bright and beautiful system of water-pictures, of many 
kinds, bolder and more vivid than those of any other bird we know (with the 
possible exception of Steller's Eider). For the most part, these pictures are 
of shore- and sky-reflections, subtilely and richly intermingled, and comprising 
a great variety of effects. The colors are mainly deep and soft, though rich, 
and liquidly alive with sober iridescence. Their range (excluding the sandy 
flanks) is from chestnut red glossed over with purple, through all degrees of 
blue to golden green; — ^perfect woodland water colors, all of them. Olive- 
ash color occurs on the lesser wing-coverts and primary quills, and this, the 
tint of lusterless still water near the shore, between reflections, is a connecting 
link between the brighter water-pictures and the sand-colored sides. The 
scapulars, which meet over the back, are somber blackish, with a glimmering 
of blue; water deeply shaded, showing a dark bottom, or reflecting something 
dusky. The "speculum" and some of the greater wing-coverts, together 
forming a patch which intervenes between the back and flanks, and, longi- 
tudinally, between the two areas of ashy olive, are bright and lustrous blue, 
ranging from almost purple to deep robin's-egg, and including also, on a single 

66 



feather of the speculum, a blended patch of copper red, sometimes combined 
with greenish bronze and purple. All these feathers are iridescent, but their 
changeableness is mainly from dusky to bright, rather than from one bright 
tint to another. They render beautifully a portion of the surface of the dim 
translucent water where there is a somewhat vague reflection of the sky or of 
plants above. Forward, this patch is blended softly into the ashen olive of 
the wing-coverts; while the speculum is bordered outwardly with a band of 
white — ^like a sharp streak of the clearest sky-reflection on the elsewhere dim, 
semi-transparent water. So, in lesser degree, with the grayish-white longi- 
tudinal stripe formed by the outer veins of the folded primaries, above sharply 
bordered with dark blue (the outer veins and a narrow stripe next the shaft 
on the inner veins of the primaries), and forward blended smoothly into the 
ashen-olive patch at the bases of the primaries. This combination of softly 
blended with clean-cut, sharp-edged markings is what gives the water-picturing 
its peculiar magic, for it represents the two main characteristic elements in 
the aspect of quiet water, namely, vistas through the surface into the liquid 
depths, and rejections, on the surface, of things above. As in the duck's 
costume, so in the water which it pictures, these two elements are now sharply 
differentiated, and now intimately blended. 

Most potent of all, perhaps, are the pictures of reflection on the Wood 
Duck's richly crested, green and purple head, with its clean-cut stripes and 
bars of snowy white. These white marks picture bright and sharp reflections 
of the sky (their sharpness of outline caused perhaps by straggling wavelets 
which 'cut' and border them) lying on the dark, translucent water, tinted 
by vague reflections from the shore. Or, again, the white and dark marks, all 
together, suggest a definite, fixed reflection-picture of a fringe of bushes along 
the shore, with the bright sky beyond cutting in among their crowns, and show- 
ing here and there between them, lower down. The white on the head and 
neck and cheeks shows duly bright, while that on the throat, from which the 
higher spots are offshoots, is, in the bird's normal life-postures, dull with 
shadow, and belongs mainly to the obliterative shading. In the resultant 

67 



water-picture it renders a duller sky reflection, mixed perhaps with under- 
water effect. 

The deep chestnut breast is blended above into dusky olive, on the fore- 
back and neck, while below it fades away into the immaculate white belly, 
the transition being effected by a series of triangular white flecks, extending 
downward in crescendo progression from the upper breast. (See, in con- 
nection with this and other points in my description. Plates III and IV.) This 
rich and lustrous chestnut, fleckless in its anterior and upper third, and glossed 
with purple and weak green, is an admirable picture of translucent, shaded 
water near the shore, either reflecting faintly the muddy bank and brown- 
stemmed bushes, or dimly revealing its owii dusky, earth-colored bottom. 
Bounding the back edge of this chestnut, and separating it from the wing 
and side, is a bold 'secant' band of black and white (like that worn by certain 
teals, but stronger), vertically. extended, but slightly crescentic, and pointing 
forward. Sharply 'secant' — seeming fairly to cut the bird in halves — this 
marking is also intermediate in character between the reflection-picturing 
patterns of the head and the ripple-pictures on the flanks. For it depicts 
with almost equal fidelity at least two types of detail — a, narrow sky vista 
reflected side by side with a dark stem or tree trunk, and a sky reflection 
glancing from the side of a sharp, single ripple. At least two evident purposes 
are likewise served by the beautifully graduated white triangles on the chest- 
nut breast, downward growing larger and larger until they completely veil 
the brown and blend it into the white of the belly. First, they are agents in 
the obliterative shading, and second, they admirably picture small glints of 
bright reflection on the faintly tremulous surface of quiet, shaded water. In 
this function they are the same as the punctate shine-pictures on the backs of 
rails, wood sandpipers, loons, etc., mentioned earlier in this chapter. 

Chestnut like that of the breast, but more strongly glossed with purple, 
forms a broad patch on either side of the Wood Duck's rump, back of the 
ripple-picturing flank feathers. It is unflecked, and blends into the dusky 
and velvety-blue-green tail, just as the breast's chestnut blends into the olive 

68 



back. Downward, this rump-mark blends into dusky-olive under-tail-coverts. 
Tail and rump together picture a patch of dark water, with blended, weak 
reflections, relieved by a streak or two of reflected shore-color in clearer defini- 
tion. These streaks, which are shining rufous brown, are formed by the 
central barbs of two or three of the loose-webbed, lengthened upper-tail-coverts; 
they relieve against dusky green. 

The ripple-, sand-, and water-shimmer pictures on the Wood Duck's flanks 
have been described in an earlier part of this chapter, but to complete this 
elaborate account we must revert to them, describing them in greater detail. 
The whole extent of the sides and flanks, from the crescent breastmark to 
the chestnut patches on the sides of the rump, is occupied by a uniform pat- 
tern of minute black vermiculations or undulatory lines, closely crowded over 
a ground-color of light brownish yellow. Below, this patch fades into the 
white of the belly; above, from a point barely in front of its middle backward, 
it is bordered by the remarkably bold and vivid ripple-pictures already men- 
tioned, formed by broad, alternate bands of snow and jet. These bands are 
on the tips of the longest of the grizzled feathers, and, as has been told, they 
cross them transversely, yet by the curling upward of these feathers the bands 
are made to form oblique or even horizontal streaks. Rising out of and sur- 
mounting the grizzled brown — ^which pictures either tremulous, opaque water, 
or, more vividly, a submerged bed of sand — these richly contrasted black 
and white streaks and crescents look wonderfully like a crowded company 
of fresh-made, hurrying ripples; just such, in fact, as the swimming bird him- 
self produces. Thus the ripple-marks he leaves in his wake and those that 
roll out from his further side are continued and repeated on his obliteratively- 
colored body, and this gives the final touch of perfection to his 'vanishment.' 
In the marvelous completeness of this 'vanishment,' this 'invisibility' in full 
and near view on quiet water, he is possibly unique among swimming birds. 
One may scan a Wood-Duck-haunted pool for many minutes, at close range, 
and fail to see the ducks that are floating on it; just as one often looks in vain 
for the Ruffed Grouse that is perching motionless in the apple tree. Like 

69 



the grouse, like the summer ptarmigan and the woodcock, the duck is, as it 
were, 'dissolved' into its vari-patterned background, by perfect obliterative 
shading and picture-pattern. 

Two details of the male Wood Duck's costume have yet to be mentioned, 
his gaudily-painted bill and his marbled under-wing-coverts. The bill is 
marked with bright yellow, red, white, and black, and in connection with the 
varied water-scene rendered by the bird's plumage, it must often pass for a 
reflection-picture of bright-colored things like flowers, on the shore — or per- 
haps for the actual blossoms of water plants. But it is to be supposed that 
the flowerlike aspect of the bill renders its owner a still more direct and simple 
service, by separately disguising that implement of offense from the insects 
and other small but active creatures which form a part of his diet. A pied, 
flowerlike bill would probably, in the long run, succeed better in the capture 
of its agile prey than would a dull and normally tinted one, without deceptive 
color or markings. Of this the reader is to hear more in a later chapter. 

The use of the black-and-white marbling of the under-wing-coverts and 
axillars, shared by both sexes, is not surely apparent. But it seems likely that 
both the color and the markings of these feathers serve chiefly or wholly for 
'obliteration,' coming into play when the birds are sitting and walking about 
in trees (a habit highly characteristic of the species), with wings frequently 
half spread. The ground color of white then becomes effective in neutralizing 
the shadow, as in the case of the belly, and the dusky-specks and bars constitute 
a generalized obliterative pattern tending to 'merge' the wing, visually, into 
its freckled forest background. This pattern is in fact closely akin to that 
of many out-and-out forest birds. 

The female Wood, Duck is colored much more dimly than her mate. Her 
wings alone are almost exactly the same, and fully as bright; otherwise, her 
predominant color, aside from the white of her belly, is ashen olive, lustrous 
with green and purple on the back, scapulars, and crown, verging toward 
brown on the sides and toward ash-gray on the cheeks, and reaching lustrous 
olive-green on the upper sides of the tail feathers. Her flanks show no traces 

70 



KXPI.A NATION OF PI.ATB IV 



MALE WOOD DUCKS. 



Upper one; Sketch by Abbott H. Thayer, 
Lower one: Painting by Richard S. Meryman 



These paintings show one of the very common situations in 
which the boldest contrasts of a male Wood Duck' s coloring come 
into play in preventing his showing his silhouette.. 

His dark areas, with all their varied colors, here 'become a 
part' of i the like-colored ^ark reflections in the water, and his 
wMt^' patterns exactly reproduce the bright sky-reflcctiohs, so 
that he is so to speak 'dissolved' into the scene. — ^A. H. T. 



PLATE IV 





) BAi-riMOBE 



of the sand and ripple pictures which are such important details in the ves- 
ture of her mate, being marked instead with blurred, broad streaks of pale 
yellowish gray, on a ground of olive-brown. On the whole, her costume 
lacks pronounced water-pictures, seeming to fit her rather for life in secluded 
recesses among reeds and bushes, and for perching among gray tree trunks, 
which she has frequently to do in the nesting season. When brooding, al- 
though most commonly quite hidden in a hollow tree trunk, branch, or stump, 
she is at times more or less exposed to outward view; and this fact also must 
have a bearing on the sfgnificance of her coloration. When she is sitting in 
the hollow end of a large broken branch, perhaps even with some of her fore- 
parts projecting beyond its rim, her obliterative coloration must often be most 
potent. (Audubon has figured a female Wood Duck in such a situation,and 
mentions it as not uncommon.) But aside from their probable connection 
with her ordeal of brooding, and guarding her ducklings among the reeds and 
bushes, her soft markings and colors and perfect counter shading make her 
at all times a thoroughly 'obliterated' bird — even though she lacks the bright 
and elaborate watef -pictures of the drake. Both drake and duck are among 
the world's most subtilely beautiful birds, and their obliterative coloration 
demands especial study. 

The Mandarin Duck (Aix galericulata) of- the Orient, nearly akin to the 
Wood Duck in all respects, has an equally beautiful and still more remarkable 
costume, but one which is less unmixedly of the water-picturing type. In the 
drake's dress there are a few important peculiarities which call for careful 
study of him in his home; but the female does not differ essentially from the 
female Wood Duck. 



71 



CHAPTER XII 



BIRDS OF THE OCEAN 



PURE white prevails in the costumes of the long-winged birds that habit- 
ually range the open sea, and their patterns are further characterized by 
an almost total lack of small markings. In coloration as in environment, 
they are the antithesis of the sedentary and seclusive land birds which live 
mainly on grassy ground or in the mottled realms of woodland — such as the 
ptarmigans, grouse, goatsuckers, etc., described in earlier chapters. The 
Shore Birds (Chapter X) are a connecting link between the two extremes. 
As their average environment is much more plain and simple than that of the 
grouse or ptarmigan, so are their obliterative patterns much less richly and 
elaborately wrought. The step is short from these birds of the barren bor- 
derland between earth and sea, to the long-winged rangers of the blank and 
hoary sea itself. Here are no sharp and fixed small forms at all, but only the 
eternal counterplay of two vast and simple fluent elements, atmosphere and 
water. True, even in open ocean there are characteristic patterns made by 
the moving waves and ripples, and these are reproduced on some of the ma- 
rine animals, notably certain surface-swimming fishes. (See Chapter XXIV.) 
But the coloration of the long-winged, wide-ranging sea birds copies the prev- 
alent blankness of sea and sky and cloud. Though often resting on the sur- 
face of the water, they are of course less intimately bound down to it than the 
ducks, auks, murres, etc., being in fact eminently aerial rather than natatorial; 
and this is in accordance with their wanting the wave and ripple pictures 
worn by many ducks and murres. Chief among these long-winged sea birds 
for delicate beauty of 'oceanic' coloration are the LaridcB, or gulls and terns. 

72 



Nearly white all over though most of them are, in the adult plumage, they are 
yet obliteratively shaded, having "mantles" of darker or lighter bluish gray 
on the back and wings — and in the case of many terns, crown-caps of black — 
while all the remainder of their costume, with the exception of a few more 
or less dark-marked quill feathers, is, in most cases, fleckless white. Black 
markings aside (these we shall discuss later), this obliteratively disposed com- 
bination of soft, water- and cloud-like pearly gray with bright, shadow-ab- 
sorbing white is just such a coloration as insures its wearers, whether flying 
or swimming, the greatest average inconspicuousness against the ocean. Often 
they show light against dusky water, but just as often they show dark against 
water brightly sky-lit; and hence in many intermediate cases they must pass 
unseen, matching their 'background' as does the ptarmigan or grouse in its 
appropriate domain, although so much less intricately. All this concerns the 
aspect of the gulls as seen from above, against the ocean. But they have little 
to dread from flying enemies, and the more vital service rendered by their col- 
oration is doubtless concealment against the sky above, from the eyes of aqimtic 
animals below them. Like the Snowy Owl, the white, herons and egrets, and, 
in part, the skunks, deer, antelopes, etc., to be described in a later chapter 
(Chapter XXII), these ocean-rangers are admirably equipped for incon- 
spicuousness, in a great many views, against the sky itself. Thus, even to the 
eyes of their aquatic enemies and aquatic prey, they wear the universal com- 
plete obliterative coloration. Pure white or largely pure white though they are, 
they must often relieve darkly against the sky, as always when seen directly 
overhead. In many views, on the other hand, they ' melt away ' into their skyey 
backgrounds, as do the white, masking rump-marks of many ruminants, and 
the white back- and head-patterns of many grubbing carnivores (Chapter 
XXII), etc. As the normal background of these sea birds is the unbroken sky, 
varied only by unbroken, sky-reflecting ocean, so their prevalent coloration is 
such as achieves pure and simple sky- and ocean-picturing. On most of the 
true gulls {LarincR) the white of the rump, tail, and entire underside extends also 
to the head and neck. The head's consequent lack of counter shading is 

73 



evidently more than compensated by the sky-matching power which uniform, 
pure white gives to this most vital and most dangerous portion of the gull, 
either when he is resting on the water, with head held erect, or — and perhaps 
more particularly — when, as he flies or swims, his head is stooped toward, 
to, or even beneath, the surface, in search of food. 

White or largely white-marked heads are common to a good many other 
birds, not counting the habitual swimmers, which get their living from the 
water; witness the Bald Eagle, the Osprey, the Great Blue Heron, etc. In 
all these cases they perform the same service of 'obliteration' against the 
sky. Some gulls, on the other hand, such as the Black-head {Larus ridi- 
bundus), of Europe, and the Laughing Gull (L. atricilla), of America, have 
dusky hoods enveloping the entire head. All or nearly all the kinds thus 
marked are inhabitants of bays and lakes and marshes rather than the open 
sea. Furthermore, the dark hood is worn only by the adults in the breeding 
season, when, amid the blackish mud and dusky shadows of the salt marsh 
or inland swamp, they well serve as 'ruptive'* masks. So do the jetty 
crown-caps of nesting terns — except that these belong to obliterative shading 
as well as to 'ruptive' pattern. (See Fig. 55.) Like the gulls' hoods, they 
are as a rule features of the breeding season only — in the autumn largely 
giving place to white, the regulation sky-matching color. But the black 
markings on the quill feathers both of gulls and terns are worn throughout 
the year, and probably serve both as ' distractive ' marks f when the birds 
are fishing, and as combined 'distractive' marks and 'picture patterns' when 
they are brooding on shore amid shadows and other dark landscape- 
details. 

For the most part, however, the coloration of these gulls and terns in adult 
plumage is suited to the sky and sea rather than to the land, and they are apt 
to be conspicuous on their breeding grounds, by virtue of their paleness. 
Their downy young, on the contrary, are almost always well 'obliterated' 

* See Chapter XIII, p. 78. 
t See Chapter XXII, p. 151. 

74 



by counter shading, color, and near-ground markings.* (See the young gulls 
in Fig. 75.) Mottled brown, dusky and gray costumes of various degrees of 
darkness are worn for two or three years by the young of the larger gulls, 
and it is a noteworthy fact that during this period they are more addicted to 
living on and about mud-flats, marshes, and muddy lagoons, than are their 
white and free-sea-ranging parents. 

Among the other groups of long-winged sea birds, there is a good deal of 
diversity in coloration, but at the same time a persistent tendency toward 
whiteness and the lack of small markings. Sky-matching costumes, indeed, 
reach high and simple development among the gannets, tropic birds, alba- 
trosses, fulmars, and others. 

The smaller jaegers or robber gulls {StercorarincE) have in the usual adult 
plumage full obliterative shading, being fuscous brown or slaty gray above, 
and white below, sometimes with small markings (dusky flecks) on the breast 
and sides ; and their young wear a heath- and grass-picturing pattern of brown 
and dusky. But the symmetry of these facts is marred by the existence in at 
least two of the three or four white-breasted species of a second adult color- 
phase, in which the costume consists of sooty brown with a comparatively slight 
counter shading. Here, as in the case of the black leopards and jaguars (see 
Chapter XXI, p. 133), there may be something to discover in the way of cor- 
responding varietal peculiarities of habits. But jaegers are parasitic harriers 
of other birds, and prodigiously swift of wing, so that, except during the 
nesting time, they doubtless have comparatively small need of disguising- 
coloration. Strange as it may seem, however, a good many other aerial sea 
birds are colored much like the melanistic jaegers — i. e., almost uniformly 
dark brown or black above and below. Such are several of the Tubinares, — 
shearwaters, petrels, albatrosses. But almost all these birds, in addition to 
being largely nocturnal, nest in dark earth-burrows or rock-fissures, and this 
habit has doubtless a significant connection with their queer coloration. 
Many other species of the same families, as well as various long-winged sea 

* See Chapter XIV, pp. 82 and 83. 

75 



birds of other orders, are obliteratively shaded, from pure white to dusky 
brown or gray, with or without connecting middle tones. Though often very 
inconspicuous against the sea, such dark-backed birds are of course less well 
equipped for 'vanishment' against either sea or sky than are the beautiful 
white and pearl-gray guUs and terns. These have, indeed, the very acme of 
oceanic obliterative coloration. 



PLATE V 




I 



BD "S ^ 







o 



1 -1 S i S 



CHAPTER XIII 

BIRDS, ETC. THE INHERENT OBLITERATIVE POWER OF MARKINGS. 
'RUPTIVE' AND 'secant' PATTERNS, ETC. 

UP to this point we have considered markings and patterns almost solely 
as adjuncts and dependents of obliterative shading. As far as ground- 
haunting species are concerned, this function of markings seems by far the 
most important, but they have yet a separate and inherent significance, which 
among non-terrestrial species is often the dominant feature of disguise. As 
we have seen, perfect uniformity of coloration makes a thing conspicuous, 
allowing every part to assume exactly the aspect dictated by its own form, 
without exaggeration or omission. Markings, on the other hand, of whatever 
sort, tend to obliterate, — to cancel, by their separate and conflicting pattern, 
the visibility of the details and boundaries of form. The main solidity, and 
its details, are shown by graduated light-and-shade — the outline, the external 
contours, by relieving either light or dark or differently colored against the 
background. To all this markings are unfriendly, both on objects actually 
monochrome and therefore visually not so, and on objects which present, with 
the aid of counter shading, a perfectly monochrome appearance. Rapid 
and manifold are the vicissitudes of illumination and relation to background 
of a moving bird, or butterfly among trees and open spaces. Now it is dark 
against a sky vista, or against brightly-lighted foliage, and the next instant, 
by some slight change in its position, or in that of the beholder, it shows light 
against dark shadow-spaces. (See Figs. 56-57.) Delicate picture-patterns 
cannot avail against these grosser 'visibilities,' but strong 'secant' and 
'ruptive' patterns can. If the bird's or butterfly's costume consists of 
sharply contrasted bold patterns of light and dark, in about equal propor- 

77 



tions, its contour will be 'broken up' against both light and dark — light 
failing to show against light, dark against dark. Such is apparently the basal 
and predominant use of almost all the bolder patterns in animals' costumes. 
Often such bolder markings play a part in subtler schemes of picture-pattern; 
but, on the other hand, they sometimes work independently of obliterative 
shading. 'Secant' patterns, however, are almost always in its service, even 
when they have some share of independent effect. A good example is the 
longitudinal light-colored stripe on the scapulars or wing feathers, so very 
prevalent among obliteratively colored birds — ^particularly those with highly 
developed picture-patterns. It is found in its perfection on certain sparrows 
and many gallinaceous birds. In almost every case it clearly pictures a 
horizontal stick or grass-blade, with its shadow under it; but, picture or no 
picture, it tends to cut the aspect of the bird in two. This marking 'is found 
also on certain kinds of wood frog, and on toads. (See Chapter XXIV.) 
There are also vertically 'secant' markings, e. g., the white or black-and 
white breast-bands of some teals (Nettion), and of the Wood Duck (Aix), 
both mentioned in an earlier chapter. 'Ruptive' markings, in general, are 
bold, massed patterns of contrasting shades and colors, disposed at seeming 
haphazard over the animal's body, but in reality arranged according to the 
rigid laws of disguise. Among birds thus marked, some of the best examples 
are sea fowl. Eider Ducks, for instance. Male Eiders, with their big, con- 
trasting patches of black and white and buff and green — or grayish blue — 
are doubtless very inconspicuous in deep ocean water among ice cakes; while 
their brown, grass-patterned mates are well fitted for the task of brooding 
their eggs on the dry shore. The non-counter-shaded male Harlequin Duck 
(Histrionicus histrionicus), likewise, is in aspect cut to pieces by its queer, 
black-rimmed white markings, which look like floating bits of ice, or patches 
of snow on rocky shores. Many other sea ducks wear kindred markings, 
and so do many land birds and even quadrupeds and other animals. The 
more crudely-blotched black and white patterns of certain woodpeckers, the 
black caps and white cheeks of nuthatches, and the various bold head-markings 

78 




Fi(i. 56. Two artificial buttei-flics, one dusky and one light, seen against a dusky tree- 
trunk; the light one conspicuous, the dusky one barely distinguishable. 




Fig. 57. The same two artificial butterflies seen against a light background, the dusky one con- 
spicuous, the light oneharely distinguishable. 



These two pictures show that no one color will conceal an animal that must move across the varied.and varying face of nature. 

In our pictures of artificial models we have purposely ignored the factor of interposed vegetation, which in nature plays so large 
a part in abetting 'vanishment' by obliterative costumes. For we are here studying main principles, divested as far as possible of 
accessories. 




K ~ 



B 3 











1 ^"^V, "^ "^ / 1^'V~-- '~."^^-^^i' i 


1 ■•^■if^k^ 






Fig. 60. Blue Jays 
at their nest, amid 
foliage. [See p. 110, 
Chap. XIX.] 



l^^flB^Ad"- 


M ■*, m 


J^ 


'" v^riBB 


-^. 


'i'^tfm^yi 


i/fj^ 


Mi?*"" 


, f ^^ 


^ ^ 


H 




^Sb^'A 


i% 


.« 


wi.\^^^^\ 


j^i;^*;^;?;- 


- . ^^ -«' ■ 


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Wl* ! ,i^ 










Be^-''! >-' 


HBaBr 


■*^Hw 4* 


r JM 


m',l,Sf 




Ik :rf 


^^H^^^e"^ ^ '^^ 


^1 


i^?- 


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It 

















Fig. (ll. Chickadee at 
nest hole. Light-aud- 
shadow-picturing general- 
ized obliterative pattern, 
most potent in snowy win- 
ter. Notice how the black 
head - markings 'merge* 
with the dark hole beyond. 

Photojjraphetl from life by 
Finley and Bohlman. Courtesy 
also of "The Condor." 




Fig. 62. Oystercateher {Haematopm ostralegus) close to its nest on rocky ground 
Counter-shading and 'ruptive' pattern, etc. 

Photogrraphed from life by Cherry and Richard Kearton. Courtesy alao of Cassell & Co. 



3 

CO 









2ig 



J 5 




of North American Wood Warblers {Mniotiltida), are a few of the many ex- 
amples among the smaller land birds. (See Figs. 58-61.) 

It might be supposed that a marking in such rank violation of the para- 
mount 'obliterative' principle as a jet-black breast or beUy, with lighter 
tones above it, could not fail to make a bird exceedingly conspicuous; but this 
is by no means true. Such a marking, especially when it ends sharply against 
a lighter tone, thence upward counter shaded, tends in aspect to detach itself 
from the rest of the bird's dim body, and to unite with the background as a 
hole or other very dark detail, thereby 'breaking up' its wearer's character- 
istic form. This is the coloration for instance of the Black-bellied and Golden 
Plovers (Charadrius and Squatarola) in summer plumage, and of the adult 
male Massena Quail {Cyrtonyx montezumce and its subspecies) of Mexico, 
etc. In the case of such birds as the male Eider Ducks, however, there is 
virtually no counter shading above or below, — the obliterative scheme con- 
sisting almost wholly of a series of 'breakages' achieved by sharply contrast- 
ing patches. 

All these bolder schemes of pattern mask their wearer in a distant view 
and in many views, whereas the delicate picture-patterns based on perfect ob- 
literative shading play their full part only in a near view and against one par- 
ticular type of background. In such a case, details of light-and-shade and 
minor surface markings count for much. But give the object a greater dis- 
tance from the beholder, and manifold vicissitudes of position and illumina- 
tion, and it is contour that betrays it — contour, relieving with varying degrees 
and kinds of conspicuousness against varying backgrounds. Combating 
this principle, Nature has given many of her animals bold and brilliant 'rup- 
tive' patterns, which insure them, in lieu of elaborate and single background- 
matching, the highest average of fragmentary background-matching, in many 
situations and from many view-points. (See Plates V and VI.) 



79 



CHAPTER XIV 

SPECIAL FUNCTIONS OF MARKINGS. BIRDS, ETC. PROTECTIVE COLORATION 

OF NESTLINGS 

HEEDING henceforward the axiom established by the foregoing chap- 
ters, viz. : All markings and patterns whatsoever are, under ordinary out- 
door conditions, unfavorable to the conspicuousness of the thing that wears 
them, we will examine further special phases of disguising-pattern in the 
costumes of birds and other animals. 

A noteworthy type of generalized picture-pattern occurs, the world over, 
on the wings and tails of hawks and owls. Most of them have, in some 
plumage, conspicuously banded quills, whose pattern shows to best advantage 
on the underside. On some kinds, like the Goshawks (Astur atricapillus 
and A. palumbarius) in juvenile plumage, these bars on the quill feathers 
form, when the tail and wings are broadly and fully expanded, a large series 
of almost complete concentric circles. Potent must be the obliterative effect 
of such a pattern, to the victim at whom the hawk is dashing, or above whom 
he is momentarily poised, with widespread tail and wings. The reduplicate 
circles of alternate light and dark, extending from the hawk's dim, streaked 
body to the very tip of his great flight-feathers, and averaging more sharply 
visible than the actual contours of the wings and tail, practically efface those 
members, so that for an essential instant he is as it were dissolved and blended 
outward, from a central core, into the banded and streaked promisfcuous pat- 
tern of the twigs and branches behind and all about him. His menacing 
body is the inconspicuous center of a maze of forest-colored circles, bewilder- 
ing and confounding to the terror-stricken creature on whom he is about to 
pounce. (See Figs. 64-66.) The light bands in these patterns of hawks' 

80 















mm 




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Il 


^mJ 


in 


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m. 




d 






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'•'^^: *»^^ Safe 





Fig. 64. Stuffed Goshawk {Asiur africapn/t(.s, young) in winter pine woods, 
seen from below as the hare or grouse would see him, wonderfully matching, 
with the help of counter-shading, his barred background of twigs, skv-glints, 
etc. 




Fig. 65. Part of a Goshawk's wing seen from 
below against pine twigs and sky. [Cf. Figs. 64 
and 66.] 




Fig. 66. The same young Gos- 
hawk (Astnr atricapillv^) laid on its 
back on the forest floor and looking 
conspicuously bright. . This reveals 
the part played by counter-shading 
in the 'twig matching' shown bv 
Fig& 64-65. 




Fig. 67. Baby Golden Plover {Charadrius 
Julvus) . Counter-shading and blotchy ground- 
picturing pattern, eye-masking pattern, etc. 
Phototp'aphed from life by Cherry and Richard 
Keanon. Courtesy alBO of Cassell & Co. 




Fig. 68. Ringed Plover {AegiaUtu hiaticula). Eye- 
raasking and 'obliterative' shadow-and-hole-picturing 
pattern. His black marks, as the reader will see, ally 
themselves wonderfully with the dark fissures in his 
background. 

Photographed from life fey Cherry and Richard Kearton. 
Courtesy also of Cassell & Co. 







^■j<v-:.«^M^«i^'r^;'^,- 



^.^A' '^*^ 








Fig. 69. Lapwing 
( Vane/lus capella) on its 
nest Obliterative shad- 
ing, eye-masking and 
shadow-picturing oblit- 
erative patterns. 

Photographed from life by 
Oherry aaid Richard Kear- 
ton. Coiii'teev also of Cas- 
sell & Co. 



wings and tails are almost always very translucent, and contrast brightly with 
the opaque dusky bands, even when the wing or tail is seen from below, and 
deeply shadowed. As the pictures show, the dark marks are just of one 
'value' with the darker twigs and branches, and the light bands between of 
one value with the interspaces of foliage transfused with skylight, against 
which the branches and twigs 'relieve.' 

Another noteworthy detail of the independent efl&cacy of pattern is the 
masking of birds' and mammals' eyes.* Markings of this kind occur chiefly 
on predatory mammals, and on birds. See, for instance, the young plover's 
head in Fig. 67. Notice the dark ring surrounding the eye, and the longi- 
tudinal dark mark at either end of it — a 'stringing out' of the eye's dark 
tone. Patterns like this, but often bolder and more varied, surround the 
eyes of many birds and a few quadrupeds. The lengthwise stripe, especially — 
the dark line which the eye seems scarcely to interrupt — is a very common 
marking among birds. This seems to be a 'conventionalized' eye-masking 
pattern, like the conventionalized ground pattern of larks and sparrows. It 
is very effective, however, as it completely breaks the eye's otherwise conspic- 
uous circular or oval outline. Other, more varied patterns achieve this in a 
still higher degree, often seeming to absorb the eye into themselves as one of 
the details of their irregular form. (See Figs. 67-72.) Light-colored eyes, 

* Many, herbivorous mammals have dark and lustrous eyes, surrounded by a more or less dis- 
tinct pale-colored ring. This, however, belongs to the obliterative shading, playing its full part of 
shadow-neutralizing when the eye is shut. Very likely the noticeableness of the open eye does the 
animal good service when it is skulking, inasmuch as it increases the likelihood that the skulker will 
know the instant he is surely detected by an enemy. All the rest of him is almost or quite 'oblit- 
erated,' but there is still much chance that a predatory creature, hunting by scent as well as by sight, 
may discover him. Because of this chance, he must be alert, ready to leap and run at any moment, 
and must keep his eyes open, even though they may help to reveal him. But their very conspicu- 
ousness increases the chance that the predator, having followed his quarry up by scent, or coming 
suddenly upon it, will look first directly at those its points of vital watchfulness, thus giving it the 
beneficent timely warning — the sure and instant signal that the crouching ' game is up ' — which would 
be lacking if the hunting-beast first recognized some other portion of its quarry's body. Encircling 
marks and all, the eyes are small details of the 'obliterated' creature, and cannot attract the pred- 
ator's attention unless he comes almost within striking distance. 



especially thdse with narrowly slit pupils, are often very inconspicuous, in 
themselves. The green and yellow eyes of many felines, especially when they 
are surrounded by irregular fur-patterns of about the same shade, are insid- 
iously unapparent and elusive, 'merging' well with leaves and foHage-vis- 
tas, etc. This obliterative coloration of cats' and other predatory creatures' 
very eyeballs must be a great aid to them in their stealthy stalking of their 
prey. An eye like that of the Copperhead Snake (Chapter XXIV, Plate XI), 
with its narrowly slit pupil, is as well concealed as any part of the creature's 
obliteratively colored body. 

One more subject which must have a place in this rather miscellaneous 
chapter is the coloration of birds in downy nestling plumage. Passerine 
birds — most of them at least — are born naked and absolutely helpless, re- 
maining in this condition for days. But they are almost always domiciled in 
substantial nests, which in their turn are usually hidden amidst foliage, so 
that the youngsters are well shielded from their foes. Such birds have no 
true downy plumage, but pass from nakedness into a coat of frowzy contour- 
feathers, marked somewhat differently from those of their parents, though 
often much resembling them. But there is a great group of birds, including 
most of the members of most of the orders outside of Passeres, whose young 
are born with a full downy covering, which they retain for many days. Such 
are the grebes, ducks, geese, gulls, terns, rails, shore birds, Gallina (grouse, 
etc.), goatsuckers, hawks, owls, etc. Of these the terrestrial (and aquatic) 
forms concern us most, for they are more exposed to danger, and have more 
highly developed protective coloration, in the infant state, than the nesters in 
trees. The terrestrial (and aquatic) assemblage may be again divided into 
two sections, one including the species whose young are for a time sedentary 
and helpless, and the other those whose young are active and alert from the 
moment of birth, and leave the nest almost at once. Of the active sort are 
grebes, ducks, rails, sandpipers, and all tne gallinaceous birds; while goat- 
suckers, and, to some extent, gulls and terns, belong to the sedentary type. 
Young grouse and other Gallince acquire the power of flight, along with con- 

82 




Fig. 70. Killdeer Plover on its iiest. [Cf. Fig. 71.] 
Photographed from life by Dr. Thos. S. Robeits. Com-tesy also of "Bird Lore.'- 




Fig. 71. Killdeer Plover over its nest Obliterative shading, shadow-picturing patterns, etc. 
Photographed from life by Dr. T. S. Roberts. Courtesy also of " Bird Lore." 




Fig. 74. Nighthawk {Chordeilesvirginianits) chick— obliteratively-shadecl, and further 'merged' into its background by blotchy 
ground-picturing patterns. 

Photographed from life by F. H. Herriclc- Courtesy also of G. P. Putnam's Sons. 




Fig. 7.K Baby Com- 
mon G\\]\f,(LaTus camis) . 
Spotty ground-picturing 
pattern, liketheshadows 
among pebbles, etc. 

Photographed from life by 
C. and K. Kearton. 



Fig. 76. Baby Cur- 
lew. [Cr. Fig. 73.] 

Photographed from life by 
C. and R. Kearton. Cour- 
tesy alec of Cassell & Co. 





Fig. 77. Young Crested Grebes. Highly-specialized obliterative picture-pattern (with obliterative 
shading.) 

Photographed from life by Cherry and Richard Kearton. Courteay also of Cassell & Co. 





Fig. 78. Baby Red-breasted Mergansers (Merganser seirator). 
Water-shine-and-shadow patterns, etc. 

Photographed from life by Cherry and Eichard Kearton. 
Courtesy also of Cassell & Co. 



Fig. 79. Sketch suggested by the young mergansers in Fig. 78 to 
show how closely they represent a little wet spot m a swamp. 




Fig. 



Young Horned Grebes on their nest, Obliterative shading and specialized ground-picturing patterns. [Cf. Fig. 77.1 

Photographed from life hy Herbert K. Job. 




Fig. 81. Baby Woodcock (PMoAeia mmor). Picture-pattern, based on counter-shading. Notice, here and in Fig 82 Babv Wnodraft 

the next figure, the perfect picturing by these young birds' patterns ot dark holes and lighted details. (PUlohela minor). [Ct. Fig. 81 1 

Photoeraphed from life by E. G. Tabor. Photographed from life by E.G.Tabor. 



tour-feathers and elaborate picture-patterns, at a remarkably early age — 
while they are still mere chicks — but with this and a few smaller exceptions, 
there is much sameness in the baby plumages of the many members of these 
widely separated orders. (See Figs. 67 and 72-76.) Pure obliterative shad- 
ing is universal among them, occurring fully developed even in species whose 
adult plumages lack it. Their color varies correspondingly to that of their 
normal surroundings; those which are raised on the rocks, like terns and 
nighthawks, being grayer, as forest-hatched grouse and whip-poor-wills are 
browner; but there is a prevailing tone of dim-brown ground-color by which 
the variations are connected. The patterns of these youngsters, too, are 
nearly all much alike. Grebe chicks, young woodcocks, and some young 
ducks, with their fantastic obliterative spots and stripings (see Figs. 77-82), 
are exceptions; but most of the other kinds, from gulls to goatsuckers, wear 
on their baby-down a soft, blotchy speckling, which seems to be the nearest 
approach to a near-ground picture that the weak, hairy feathers can produce. 
But this pattern serves admirably to merge the little, counter-shaded puflf 
of a chick into its immediate background of rock or pebbles or leaf-strewn 
forest earth. The 'obliteration' indeed, strongly abetted by the chick's 
form-belying, ambiguous fluffiness, is often perfect. (See Figs. 48, 72, 74, and 
82.) Young ducks and geese, living much among green reeds and grasses, 
are more or less strongly tinted with greenish yellow, but their markings are 
usually very simple. Baby plovers and sandpipers (Figs. 72 and 76) have a 
dainty and effective pattern, though still more or less of the blotchily speckled 
type, and are counter-shaded to a nicety; as are, indeed, almost all terrestrial 
downy chicks. 



83 



CHAPTER XV 

BIRDS. OBLITEEATIVE COLORATION AND MASKING OP BILL AND FEET FOR 

OFFENSIVE PURPOSES 

UNDER this heading I shall include the pattern-bearing "pantaloons" 
of hawks, the prevailing pale or bright coloration and occasional 
counter shading of their tarsi and feet, and the various bright colors and 
occasional flowerlike appendages of the bills of jacanas, gallinules, anhingas, 
herons, etc. 

The spreading shields of leg feathers, or "pantaloons," worn by almost 
all hawks and some owls, and almost peculiar to them, must naturally be 
supposed to have some connection with their predatory grabbing-habits. 
But what is the connection — what the function of these pantaloons? One 
use they have, and a seemingly important one, is this: they act as masks of 
the dangerous talons, by making them appear merely as spots merged into a 
moving veil of patterned feathers. If the extended legs and feet were stark 
and narrow, without adornment, they would be much more clearly visible 
to the animal attacked. As it is, the deadly feet descend in a broad and 
blurring haze of mottled feathers, which must certainly reduce the victim's 
chances of successful dodging. The bold form of the hawk's long leg is 
veiled by these tufted feathers, and still further concealed by the pattern of 
spots or transverse bars which these feathers bear. On some species, such 
as the Rough-legged Buzzards (Archibuteo) of the North, and the Harpy 
Hawks (Spizaetus) of South America, the entire tarsus is concealed by feathers, 
usually covered with bold patterns (sharply cut by transverse barrings in the 
Harpy Hawks) ; but most species have the tarsus as well as the foot bare for 
action. Most owls, on the other hand, have everything but the very claws 

84 



muffled with feathers. The bare feet of hawks are usually very light in color 
— ^yellow or livid green or orange, — oftenest yellow. These pale, bright colors 
have a deceptive effect, inasmuch as they are less characteristic of hard ani- 
mal substances than of leaves and flowers and grasses. Furthermore, they 
tend to prevent the feet from looming darkly conspicuous, as they otherwise 
would in the shadow of the body. In the case of the Osprey or Fish Hawk 
{Pandion), whose spur-scaled foot has such a marvelous tenacity of grip. 
Nature seems to have used her utmost skill in the manufacture of a perfect 
fishing weapon. Not only are the tarsus and toes pale watery blue and green 
in color, but there is even a perfect obliterative shading from the top to the 
bottom of the foot. The pantaloons are obsolete, and all the leg feathers are 
immaculate white — details in most evident harmony with the habits of the 
bird. Spreading leg feathers would obstruct action in the water, and mark- 
ings would be equally out of place, since they belong properly to the inhabi- 
tants of the streaked and mottled realms of field and forest. Pure white, on 
the other hand, is less conspicuous than any other tone or color when seen 
from below against the sky, or against the body of the bird above, whose 
interposed opacity additionally steeps the leg in shadow. 

Of one class with these masking-devices of hawks' legs and feet are the 
bright and motley bill-colors of predaceous wading birds and swimming birds. 
Whatever may be their other functions, these gaudy colors well serve to dis- 
tort, conceal and mask the powerful beaks, to the vision of the fishes, frogs, 
insects, etc., in the capture of whom they are employed. Some of these 
beaks, such as those of many herons, of anhingas, etc., are marked with bril- 
liant reed- and water-colors, in various forms and combinations. Others, such 
as those of rails, gallinules, jacanas, etc., are like bright leaves, stems, or 
flowers — green, yellow, orange, or scarlet, as the case may be, in varying pat- 
terns, sometimes combined with water-like blues or purples. (Ceirtain South 
American frogs are clad in these same colors. See Belt's "The Naturalist in 
Nicaragua," p. 321.) Some of the jacanas have flat, erectile lobes or wattles, 
of a rich red color, set about the base of the yellow bill, like red petals around 

85 



a golden corolla.* Many of these wading birds have also reed-colored or 
otherwise deceptively painted legs and feet, which may often save them from 
being snapped up by alligators and turtles, and must also help them in their 
hunting. 

The study of the colors of birds' bills and feet in relation to their habits 
and environments is a large field in itself, and we in this chapter have barely 
peered over its borders. But there seems little room for doubt that the gen- 
eral principles here briefly stated are dominant or at least very important 
ones. 

* It is most noteworthy that scarlet and yellow, the colors of the flowers and leaf stems of the 
"cow lilies" which aboimd in North American swampy ponds, are also to be found on a great many 
of the animals that resort to these places. The Wood Duck, the Gallinules, the Red-winged Black- 
bird, and the Painted Tortoise, for instance, all wear scarlet, black (or dark blue) and yellow, just as 
does the surface of such a pond, with its black shadows between the lily pads and flowers. Even 
the long-billed Rails of the same region have (in spring and summer) coral-colored beaks. Indeed, 
red, orange and yellow seem to be very common colors of aquatic vegetation and of swamp birds' 
beaks, the world over. 

From a hawk's point of view, as he flies over swamps and ponds, it is not merely the black water 
itself that these species match, but also the dark mud, and, in general, the dark spaces between the 
vegetation. From overhead, the Red-winged Blackbird, even when perched on top of the bushes, 
matches — or simulates — the shadowy spaces beneath; and his faintly discernible outline is easily 
rendered indistinguishable by the conspicuousness of his scarlet and yellow cow-lily picture (just as 
the letters in Fig. io6 are made illegible by their patterns) — in spite of his lack of counter shading. 
In fact, though the 'Redwing' often perches high enough to show black against the sky, to us, to the 
soaring hawk he is commonly matched to the mud, as much as rails or coots. — A. H. T. 



86 



CHAPTER XVI 

BIRDS, CONTINUED. 'OBLITERATION' BY IRIDESCENCE. CHANGEABLE COL- 
ORS IN GENERAL; THEIR PART IN WATER-PICTURING COSTUMES, ETC. 

BRILLIANTLY changeable or metallic colors are among the strongest 
factors in animals' concealment, and go far toward achieving 'oblit- 
eration' without counter shading. The quicksilvejr-like intershifting of many 
lights and colors, which the slightest motion generates on an iridescent sur- 
face, like the back of a bird or the wing of a butterfly, greatly obscures the 
visability of that wing or back, as such, tending to make it 'blend' inextri- 
cably with the gleaming and scintillating, labyrinthine-shadowed world of 
wind-swayed leaves and flowers. Even without motion, the animal's sur- 
face, which would show all in its true place and plane if it were plainly col- 
ored, is by its iridescence made to appear 'dissolved' into many depths and 
distances. Here is a bright place that stands out near and clear, there a 
dark area that melts away into'indefinite remoteness, and so on. Rarely does 
such a 'changeable' surface, out of doors, reveal itself fully and truly to the 
eye. Hence, iridescence is, as I have said, one of the prime factors of dis- 
guise, and quantities of creatures profit by it. As a general rule, it is found 
on animals that spend much of their time in lively motion. As we have seen 
in Chapter XIII, the more minutely detailed forms of obliterative coloration 
are not adapted to animals of this t5^e. Seldom "lying close," they need a 
bold and simple disguise to lessen the conspicuousness of their movements. 
This is found, as we have seen, in 'ruptive' pattern; and iridescence is equiv- 
alent to ruptive pattern with an added gift — the power of motion. Ruptive 
pattern, that is, with no fixed form, but mutable like the landscape itself. 

87 



When the iridescent-costumed animal is still, the slightest change of light upon 
him will cause a bewildering play and movement of his colors; and when he 
moves, his colors' varied dancings are far more apt to belie and perhaps con- 
ceal his motions, than to accentuate them. For instance, the gleaming high- 
light, the central point of shine on the back or side of an iridescent bird, say 
a turkey gobbler or a peacock, may move backward on the bird's surface while 
the bird himself moves forward, so that to the observer's eye it seems to be 
standing still, and since by virtue of its very brightness this spot will hold the 
attention, it must often happen that the bird seems to be motionless when 
he is in fact slipping away. It may be objected, and truly, that such decep- 
tions as this are of only momentary effect. But the reader should realize, 
in this case and in all kindred ones, that it is just these tiny, trivial seeming 
moments that often tip the balance toward escape or capture, toward life or 
death, in an animal's career. The predatory animals and the animals they 
prey upon have been developed together, and their powers of capture and 
escape interadjusted to a nicety. The business of the one kind is to hunt 
and kill, of the other to evade their clutches; both are Nature's children, both 
are favored by her, and both' grow up and survive as races in the same woods 
and fields. On the one hand, Nature fits the hunters to kill enough of the 
weaker animals to keep themselves alive as a race, on the other she fits the 
weaker ones to escape so often that their race too shall not succumb, that 
the hunting race cannot overstep its boundaries ; that, in short, the even bal- ■ 
ance between hunters and hunted shall in the long run be maintained. On 
the hypothesis of Natural Selection, we must suppose that there is the closest 
rivalry between the two opposed developments ; like the continual competition 
which has long been going on in man's domain, between the development of 
armor and the development of explosives and projectiles. To their rivalry 
alone is due the wonderful and ever-increasing excellence of both develop- 
ments, in the case of the human instruments of destruction and defense; and 
just such, if we believe in Natural Selection — or, in fact, on any hj^othesis 
that recognizes adaptation as something more than accidental — must we sup- 



pose to be the way with predators and prey in savage nature. In any case, 
it is obvious that, as things stand to-day, the very smallest items in aid either 
of the hunters or the hunted must be of vital importance. Eagles and tigers 
are not more clever at catching than their quarries are at escaping, hence the 
slightest additional aid may save a quarry's life. Just such an aid is the mo- 
mentary deception effected by the contrary movement of a spot of iridescence, 
as described above. Hindered but for an instant, the pursuer may be wholly 
balked, for that instant may enable the quarry to slip into cover, or take wing, 
just in the nick of time. 

But the larger deceptions achieved by iridescence, viz., nearly complete 
'obliteration,' in one form or another, are still more potent and important. 
A brightly changeable plumage is like a sumptuous wardrobe, packed into 
marvelously small compass — many different dresses combined in one, without 
the loss of their individual identity. The Mallard Duck (Anas boschas), for 
instance, has in some lights a bright green "speculum" on its wing. In other 
lights this mark is blue, in still others, purple. In addition to the look of life 
and motion (like that of water and glittering vegetation) which the change- 
ableness of this marking gives it, it also makes it far likelier to match the 
bird's background than any fixed tint could. Water, mirroring whatever is 
above it, varies interminably in color, and so do foliage-vistas and other land- 
scape details. Were the Mallard's speculum of a uniform blue, it would 
serve its full obliterative use only when the bird's background happened to 
show areas of just that hue. But containing as it does the whole scale of 
colors from grass-green to reddish purple, displayed one after another by 
slight changes in the bird's position, it is equipped for perfect color-match- 
ing, if often only in flashes, with many sorts of background. Indeed, even in 
most single yiews, and without motion, the speculum shows such a range of 
lustrous color that some part is likely to be an exact match for one of the back- 
ground tints. (Although this marking is usually almost hidden while the 
ducks are swimming, it often comes into full view when they walk or stand, 
as on river-banks or tussocks, or in reed-grown shallows.) Still more marked 

89 



and striking applications of the same principle occur among bright-colored 
land birds, notably tropical ones. There are species with almost the entire 
plumage highly iridescent, changing perhaps from bronzy red to emerald 
green (or even to blue), according to the bird's position relative to the source 
of light and the beholder. Such for instance are some of those exquisite 
aberrant kingfishers, the jacamars (GalbulidcB) of South America. One of them 
at least, Galbula ruficauda, the only kind my father and I have studied in 
its native forests, is exceedingly hard to discover when it is sitting stock- 
still on its exposed look-out perch low down among the trees. It affects 
semi-cleared areas, and the open reaches and borders of the forest, where 
there is much variety in the colors of its background, and there is no dis- 
puting the fact that its beautifully rich iridescence aids it greatly in escaping 
notice in these places. Its colors shift with the shifting scene, as it were; 
they counterfeit the airy life and changefulness of the encompassing leafy 
landscape, played on and vivified by wind and sun and shadow, not to speak 
of the changes wrought by the movements of the beholder. The environing 
landscape contains, in one or another degree of purity and brilliance, all the 
colors of the rainbow; and the tints of the jacamar's plumage likewise range 
through almost the entire spectrum. Often the bird's background is bluish 
green, often all his upper parts show nothing but that color; often, again, his 
background is rich reddish bronze, just such as his feathers show in certain 
other lights, and so on. Of course the changes in the bird's color are inde- 
pendent of the changes in his background, but in the long run his lively versa- 
tility of tint must enable him much oftener to match his versatile background, 
in part at least, than he could if his colors were unchanging. The jacamar is 
also a bird of the deep forest, however — not by any means confined to the 
bright-colored half-open regions — and accordingly he wears on his underside 
the regulation forest brown of tropical woodland animals. (See Chapter 
XIX, p. 107.) If a bird wears colors characteristic of his environment, it is 
not necessary for his concealment that he should momently 'match' his back- 
ground, even in part. A spot of brown, for instance, introduced where such 

90 



a spot might well occur in the background, will readily pass for a real back- 
ground-detail. 

There are two kinds of changeable color among birds. One is iridescent 
or metallic color, such as we have been considering, and the other, worn by- 
many of the most gorgeous species, is what may be called 'dead' or sheen- 
less, changeable. In this there is no sudden glinting or intricate intershifting 
of bright colors, but merely a change in the general tint of the lusterless and 
uniformly-colored surface, dependent on the complete change of its position 
relative to the source of light. This kind of coloration lacks all the subtler 
ma^ic of obliterative power possessed by iridescence, but shares to some ex- 
tent its advantage of adaptability to often-varied backgrounds. Many of the 
most brilliant blues, greens, and purples in the plumage of birds are of this 
lusterless type. Good examples among familiar species are the common 
European Kingfisher (Alcedo ispida), and the North American Indigo Bunt- 
ing {Passerina cyania). When such a bird is between the beholder and the 
source of illumination, its brightest color is a deep blue, or sometimes even 
purple. When, on the contrary, the beholder has the source of illumination 
behind him, and the bird in front, so that the light, striking it fully and fairly, 
is reflected directly back to the eye, the parts which were before dark blue or 
pyrple are clear, light green, sometimes even golden green or almost yellow. 
(For the best effect, particularly in the display of the green extreme, the bird 
should be seen head-on.) Some birds which are wonderfully inconspicuous 
in their normal haunts have this type of coloration. Such for instance is the 
American Purple Gallinule {lornis mariinica), mentioned in an earlier chap- 
ter. The changeableness of this bird's color, however, is mainly from bright 
to dim, rather than from green to purple, and does not play a very important 
part in his 'disguisement,' which is nevertheless adequate. It consists in a 
close imitation of the beautifully blended tints of quiet water amidst luxuriant 
vegetation. The soft purple breast and sides picture that part of the pool 
which is shaded from the sky, and reflects almost nothing; the bright-blue 
wing depicts the water which reflects the sky, and the green and olive back. 

91 



into which the wing's color softly blends, is a perfect match for the dim reflec- 
tions of vegetation at the water's edge. Thus the Purple Gallinule's costume 
seems to be a picture of the entire surface of a little pool among the reeds. 
It largely lacks obliterative shading, and its pattern is to some extent of 
the 'ruptive' type, the 'break' occurring between the dark-purple underside 
and flanks and the bright-blue wings. This makes the sky reflection seem 
to stop short, as if against the shadow of a water plant, while the purple pic- 
tures a darkly and graduatedly shaded portion of the pool. A kindred type 
of coloration, but one involving true iridescence, occurs on the American 
Green Herons (Butorides). These birds' costumes have perhaps even closer 
affinities with that of the Wood Duck, described in Chapter XI. Both haunt 
opener places than do the gallinules, not being dependent, as they are, on the 
shelter of the reedy jungle. In this respect, however, the Wood Duck is in- 
termediate between the other two, though nearer to the heron. Green Her- 
ons frequent the reaches of open water, and avoid the reeds; but not being 
swimmers, they are confined to the shores and shallows, and the trees and 
bushes over them. Characteristically, then, they are birds of the edges of 
small inland waters. Accordingly, we find them beautifully equipped with 
water's-edge colors and patterns. Their ash-green, delicately iridescent backs 
picture the surface of still water, faintly shimmering, and covered with a film 
of floating dust or scum, which blurs reflections. Their necks and heads, 
when brown (as in some of the species), match muddy patches on the bank, 
or mud-holes seen through shallow water, or the interior brownness of the 
trees and bushes over or beyond the water's edge, or the brown, leafy ground 
beneath them. But it is on the herons' wings that the obliterative picturing 
reaches its most elaborate development. Their ground-color is a soft, iri- 
descent, water-green, and this is broidered over with a system of delicate 
marginal stripes and bands of white and buff. These markings are so ar- 
ranged that they imitate very closely the look of green-reflecting water rolling 
in small ripples over golden sand — a most characteristic sight at the borders 
of streams and ponds. The white marks depict the ripples, and the buff 

92 



marks the sand glinting through the moving water. Again, the system of 
white and golden marks together simulates the flickering sun stripes on the 
bottom, made by refraction from the ripples. Naturally, the life and realism 
of these pictures are greatly enhanced by the iridescence of the green ground- 
color. 

There are a great many other beautiful cases of this use of iridescence in 
aid of definite background-picturing, but the above example must sufiice us 
here. One more small detail, however, one more phase of the use of change- 
able color, must be described. It is one to which I have already alluded, in 
part, in this and an earlier chapter, namely, the apparent 'opening of win- 
dows' in a dull-colored surface by the application of bright spots and stripes. 
The brightest iridescent and sheenless changeable colors are often set in 
spots like jewels in an otherwise dull costume. Common and important in " 
the case of birds, this type of coloration is even more so in that of butterflies. 
But these will be considered later, and we are here concerned with birds alone. 
Many birds, particularly tropical ones, have such gemlike spots in the midst 
of somber plumage. Often they are surrounded by dead black, or some 
very dark tone of brown or gray. This encompassing dusky pattern, being 
usually quite lusterless, is the same in all lights, while the bright spot in its 
midst flashes and alters with every little shift of light or movement of the 
bird or the beholder. Therefore it has the look of a hole in a motionless 
dark obstruction — a glimpse through a somber shadow — ^beyond which are 
seen sky vistas or the flickering light and movement of vegetation. Or, again, 
the bright spots may pass for moving bits of vegetation relieving against a 
motionless shadow or hole behind them. In either case, the solid form of the 
bird will be effectually 'cut to pieces.' 

To sum up: changeable colors of all sorts strongly tend to conceal the 
birds that wear them, and iridescence is extraordinarily potent in this way. 
Its power is of two kinds, which are, however, practically inseparable in their 
working. First, it goes far toward annulling the normal lights and shadows, 
with their color-effects, of the surface on which it is placed; and second, its 

93 



great and vivid versatility of color and shade almost insures the 'matching' 
of some part of that surface with whatever forms its background. When part 
of a bird's surface blends thus with his background, the remainder, in most 
cases, looks un-bird-like. 

Iridescence should perhaps be considered second only to obliterative shad- 
ing as a factor in the disguisement of birds; its universality attests its value. 



94 



CHAPTER XVII 

BIRDS, CONTINUED. THE ' OBLITERATIVE ' POWER OF APPENDAGES. ONE 
USE OF LONG, BANDED TAILS CONJOINED WITH STREAKED BODIES 

SINCE the simple, organic outlines of an animal's body tend to reveal it 
to the eyes of enemies, Nature has resorted to many devices in order to 
conceal those outlines. Such are various kinds of bold, contrasting patterns, 
one of whose main effects is to hide the curved, characteristic forms by letting 
into them, as it were, bays and notches of the background, of arbitrary shape. 
Appendages are exactly the converse of this. They break the normal con- 
tours by extending them irregularly outward, so that, figuratively speaking, 
the animal is pulled out of shape and 'bridged over' into its surroundings. 
"Appendages" include long tails, abnormally extended wing feathers, scap- 
ular and other tufts, occipital crests, "beards," etc., and also fleshy outgrowths 
such as combs and wattles — in short, all superadded external developments, 
whether of skin or feathers. Many of these devices must have a remarkable 
concealing-power. Think for instance of the Mexican Quetzal, or Resplen- 
dent Trogon (Pharomacrus mocinno), with its enormously long, green, droop- 
ing tail. How potently delusive to a hawk, flying over a seated trogon, might 
be this indefinite, smooth extension of its green back into the maze of leafage! 
Other notable examples are the peacocks and pheasants. In the case of many 
pheasants an additional peculiar principle comes into play. Their long tails 
are marked with strong transverse bars, of two or more colors and shades, 
like stripes of alternate light and shadow on dead leaves or earth, which tend 
to merge the tails into their backgrounds when the birds are still, and thus 
contribute largely toward their obliteration. (See Fig. 133, Chapter XXVII, 
p. 238; Fig. 120, and Chapter XXII, p. 159.) But when such a bir-d glides for- 

95 



ward, the bold transverse bars, being extended across the line of motion, make 
the movement of the tail conspicuous, relatively to that of the longitudinally 
streaked or finely speckled body ahead of it. By this device the bird's chances 
of escape from an enemy are decidedly increased. For the predator's eye is 
drawn to marks hack of the vital part of his intended victim, which is at the 
same time rapidly moving forward, hence there is likelihood that he will miss 
his aim by striking behind, perhaps capturing a tail from which the bird tears 
itself free and escapes. 

The practical force of this law of the comparative conspicuousness of 
transverse and inconspicuousness of lengthwise marks in motion can easily 
be demonstrated. One should take a ribbon of cloth, or a slender board, 
and mark half of it (one end) straightly and evenly with lengthwise stripes of 
several colors (or simple black and white), and the other half with the same 
colors in transverse bars. Then if the stick or ribbon is drawn smoothly 
across an opening,, through which alone it is seen, its motion will be grossly 
visible while the banded part is passing, and almost invisible during the passage 
of the striped half. Motion merely tends to convert lengthwise marks into 
lines, which have little or no visible activity, and may often seem to be passive 
streaks on the background of the thing that bears them. Hence the elusive- 
ness of gliding striped snakes among sticks and grasses, in remarkable contrast 
to the conspicuous movements of banded snakes. (Of this the reader is to 
hear more in a later chapter.) A practical artificial test of this effect even 
simpler than that above described, and almost equally effective, can be made 
with a white string, part of which has been marked with dark spots, and part 
left blank. The alternate light and dark spots are equivalent to the bands, 
and the unspotted part is equivalent to the streaks (being, in fact, a single, 
perfect streak). But the whole proposition is pretty much self-evident, and 
scarcely calls for demonstration. As a factor in the protection of birds and 
other animals the principle is of decided importance, and it very likely plays 
a much larger part than we yet know. Among snakes and long-tailed birds, 
particularly pheasants, its use is certainly both general and pronounced. On 

96 



the other hand, the application of such a principle in Nature is almost always 
enmeshed and interwoven with that of other principles, and this case is no 
exception to the rule. The same marks which serve to direct an enemy's at- 
tention to the tail when the bird is in motion, also serve, as we have seen, to 
picture the quiet background when the bird is still. Here, however, we have 
not the blurring counter-action of two principles, but their full coordinate 
development and perfect interadjustment. The marks on the bird's tail may 
be, and often are, beautiful pictures of leaves and sticks and light and shadow, 
as potently obliterative as any other picture-patterns; this is their function 
when the bird is "lying close." But the moment he moves they are changed 
into effective 'target marks.' The transformation is instantaneous and com- 
plete; the picture-effect wholly ceases; for leaves and sticks and lights and 
shadows are never seen to move off suddenly and rapidly over the ground, 
in a compact, unchanging company. With patterns of lengthwise streaks, on 
the contrary, there is little visible change between rest and motion, as we have 
already seen. The longer and straighter are the streaks, the smaller is the 
visible effect of their lengthwise motion, and vice versa. (The two extreme 
t5^es are of course connected by all manner of intermediates.) 

Enormously developed feather-appendages are characteristic of several 
groups of tropical birds, notably the Birds of Paradise (Paradiseidce). Hith- 
erto, it has always been supposed that male birds of paradise represented the 
very acme of avian conspicuousness; but this belief is curiously wide of the 
mark. In a museum exhibition box, amid blank walls, one of these richly- 
colored and sumptuously plumed birds is extremely shov(^ and conspicuous; 
but why should we infer from this that he must also be conspicuous in life in 
his native woods? They are not monochrome and blank, but, on the con- 
trary, full to overflowing with every possible variation of form and color, 
produced by the redundant richness of the vegetation, and the numberless 
vivid and changeable effects of sun and shade. The eye finds it hard or im- 
possible to unravel such a luxuriant labjnrinth, to separate and define the 
boundaries of its individual components. Leaves and stems and trunks and 

97 



branches, vines, fruits, and flowers, shade and sunlight — all mix and overlap 
and intertwine in the most bewildering way. Amidst, against, this intricate 
tangle, even a simple bird-shaped bird, of uniform color, would be very incon- 
spicuous; while a bird (like some of these birds of paradise) so adorned with 
grotesque plumes * and bristling, 'hay-stack' tufts of superadded feathers as 
to have lost almost all semblance of his simple bodily form, would be almost 
insured against detection as he sat or moved in such a forest maze. His many- 
colored plumose excrescences would serve with extraordinary efl&ciency to 
blend him into his surroundings — here seeming to coalesce with a bunch of 
gaudy flowers in sunlight, here with shining leaves, and there with a gulf of 
somber shade. Then, too, all irregular outward extension of a bird's form, 
amid such surroundings, increases the frequency with which parts of his out- 
line come into actual touch with like or kindred colored details of vegetation, 
thus obscuring still more potently the bird's real shape. (See Plate VI.) 

The three main obliterative agents other than counter shading, which we 
have now considered, namely, 'ruptive' patterns of boldly contrasting patches 
of color, iridescence and other changeable color, and appendages, different 
as they are in form, are yet closely akin to one another in the results they 
achieve. In one degree or another, in one or another manner, they mask the 
contour of their wearer, and 'break him up' into his background and sur- 
roundings. Kindred in character, the three principles are often combined 
in application, two or even all three of them frequently occurring in the same 
costume ; and the intricacies of their coadjustment are often very, hard to an- 
alyze. In the case of certain birds of paradise, all three principles are found 
in full coordinate development. Male birds of paradise are well known to 
have remarkable habits of raising and vibrating their plumes, as they sit in 
small companies, among the females, in certain chosen trees. The observa- 
tion of this habit has led people, most naturally, to believe that sexual dis- 
play is the sole or at least the paramount use of the plumes and gaudy colors. 

* Some of the big tufts of plumes terminate in such a fihny, hazy spray, that they can scarcely 
fail, in any view, to seem softly blended into their background. 

98 



But the assumption that their use is limited to this one function is based on 
the strangely mistaken notion that such birds are conspicuous in their native 
woods. The error has been wholly based on theorizing — collectors have not 
found the birds easy to see in their home forests, but, on the contrary, have 
often testified to the strange illusiveness of certain very gaudy -kinds, even 
relatively to their dull-colored and plumeless females. This has led to the 
belief that they are conscious of being perilously gaudy, and are therefore 
wary, and careful to keep themselves concealed amidst foliage, etc. — which is 
evidently a complete misinterpretation of the case. 

The question of how large a share, if any, sexual display has had in de- 
veloping birds' brilliant colors and elaborate appendages cannot be discussed 
here. But we have at least shown that such developments, far from making 
birds conspicuous, are all— pied-patterns, iridescence, and appendages — ^po- 
tent factors in the concealment of their wearers. Even the lesser appendages, 
such as small occipital crests, ear-tufts, wattles, etc., all tend to conceal birds 
by breaking their normal contours. 



99 



CHAPTER XVIII 

BIRDS, CONTINUED. MISCELLANY. MIMICRY AMONG BIRDS. THE BRILLIANT, 
FLOWERLIKE COLORATION OF gUMMTNGBIRDS' HEADS NOT MIMETIC. 
, SEXUAL DIFFERENCES OF COLORATION 

TWO kinds of 'Mimicry' have been described by various authors as oc- 
curring among birds; first, the form distinguished as "Protective Re- 
semblance," in which a hve animal counterfeits the appearance of an inani- 
mate thing, and second, so-called Mimicry proper, in which one animal 
counterfeits the appearance of another. But of Mimicry proper among 
birds few instances have been cited, while Protective Resemblance has been 
supposed to cover most branches of avian (as well as mammalian, insectile, 
etc.) protective coloration, including the many which we have already shown 
to belong to the very different principle of obliterative coloration. The ques- 
tion of "protective resemblance," indeed — the mimicry by animate of inani- 
mate things — is somewhat closely involved with certain phases of the oblit- 
erative coloration of birds, and must be considered here. I have mentioned 
it several times in the preceding chapters, in connection, for instance, with 
bitterns, goatsuckers, ruffed grouse and screech owls. In all these cases, 
the principle has either been dismissed as having no true application, or has 
been shown to be subordinate to the laws of obliterative coloration. The 
ruffed grouse and the screech owl draw their feathers tightly to the body, 
making themselves as thin and sticklike as possible — and this might be 
called mimicry. But, as I have explained, this very action is essential to the 
perfecting of their exquisite picture-patterns, which imitate the details of their 
more or less distant backgrounds, rather than the markings on a single fore- 
ground branch or stub. The bittern, likewise, with head and neck held stifHy 
upright, might be supposed to be mimicking a stick, but a more critical in- 

lOO 



spection reveals the fact that his head and neck picture several reed stems, 
with their shadows, and that the peculiar attitude is necessary for the most 
effective display of this obliterative or at most semi-mimetic pattern. (Semi- 
mimetic, inasmuch as the several reeds seem to occupy about the space really 
filled by the bittern's neck, although the effect is still of the neck's dissolution 
into its general background and surroundings.) But in all or most such cases, 
in spite of the evident paramount importance of the obliterative function, it is 
undeniable that the mimetic effect is sometimes achieved, to a greater or less 
extent, and hence that it must be a factor in the development of the peculiar 
actions and even the particular coloration of certain birds. Just how large 
or how small a factor, who shall say ( ?) ; but recognizing the dominant impor- 
tance of the obliterative laws even in these few special cases, one cannot sup- 
pose that the other principle has more than a very limited and slender scope. 
Nevertheless, it is not to be ignored. A Ruffed Grouse picking buds high 
up among the leafless twigs of winter trees, must often be seen in a light and 
against a background (as of blank snow) which does not favor its obliterative 
coloration. Then the extraordinarily slender, stick-like form (accentuated by 
peculiar angles in the head and neck, and by the erected occipital crest) which 
the bird assumes the moment it is alarmed, does certainly render it good ser- 
vice in the direction of protective 'mimicry.' At such times the bird's ene- 
mies must often mistake him for a knotted branch. Yet, on the other hand, 
even at such times, thanks to the bird's perfect obliterative shading and pat- 
tern, the chance is great that he will not be seen at all (as a solid object), and 
this chance is probably still of paramount importance. 

But there is one bird at least in whose case the balance of importance may 
tip toward the mimetic function of specialized perching-habits. This is the 
big woodland goatsucker of northern South America, etc., the "Poor-me- 
one" of Trinidad negroes (Nyctibius jamaicensis), whose characteristic 
perching place, both by day and night, is the top of a broken stump or up- 
right branch. Here it sits almost erect, and motionless, with its long and 
ample tail pressed flat against the side of its perch, which seems to be con- 

lOI 



tinued_ upward by the bird's dark, obscurely mottled body, terminating in the 
broad, flat head. This mimetic attitude is completely effective in the twi- 
light or moonlight, when the "Poor-me-one" uses a stump- top as a look-out 
perch, whence it launches forth on short flights after aerial insects, soon 
sailing back to cap the same or sometimes a neighboring stub. There can be 
no doubt as to the completeness and importance of the mimetic function of 
the "Poor-me-one's" pecuhar perching-habits. The mimicry, however, is 
mainly positional, or attitudinal, for it is not supported by any very particular 
developments of the bird's form or markings. The bird's mottled pattern, 
to be sure, is less exquisitely fine than that of many nearly related goatsuckers, 
and hence less well fitted to serve the full obliterative function of background- 
picturing, while it must greatly help the stump-top mimicry, especially in a 
dim light. " Poor-me-ones " have been found roosting in the daytime on the 
tops of stumps, in the characteristic erect attitude, and in these cases they 
were certainly "making a bid" for mimicry, in which both color and mark- 
ings played a part. But it is likely that their roosting-habits vary somewhat, 
as I know that their nocturnal perching habits do. They have a strong pref- 
erence for naked stumps, but I have more than once seen them sitting in the 
moonlight on horizontal leafy boughs, and even perching lightly among the 
slenderest twigs at the very tips of the branches. Assuming that there is 
equal irregularity in their diurnal roosting habits, as we may pretty safely 
do, it follows that they must often be so situated that the obliterative function 
of their coloration comes fully into play. Indeed, there can be no doubt of 
this, as they are equipped with a complete, though slight, obliterative shading, 
which hinders rather than helps the mimetic effect; and their markings, though 
relatively, somewhat crude, yet partake largely of all the elements of back- 
ground-picturing. But, from all that we yet know of the habits of this in- 
teresting bird, it seems probable that it profits at least as much by out-and- 
out mimicry (in effect) as by obliteration. This is the most pronounced case 
of the kind that we happen to know of. Others equally remarkable exist, 
no doubt; but they are rare enough to be fairly called anomalous. On the 

I02 



other hand, the cases are many of the occasional mimetic aspect of birds 
whose main protective equipment is purely obliterative, like the ruffed grouse, 
screech owl, etc., just referred to, and the terrestrial goatsuckers mentioned 
in an earlier chapter. Other slight and dubious encroachments of mimicry 
into the domain of obliterative coloration have been mentioned here and 
there in the foregoing pages, as for instance in connection with the flowerlike 
bills and frontal appendages of certain water birds (Chapter XV). 

The gorgeous "beauty spots" of hummingbirds, most commonly occurring 
on the head and throat, are certainly not mimetic, though they have some- 
times been considered so. Flowerlike though many of these brilliant head- 
dresses are, there is not, I believe, one among them all which really imitates 
a single flower, in minute and near detail. On the contrary, they are all 
flashing pictures of flowery and leafy landscape, at uncertain distances. Hum- 
mingbirds' metallic colors mark the very climax of the development of iri- 
descence, the high obliterative power of which principle has already been ex- 
plained. Their changeableness often ranges from duU, velvety soot-color to 
the intensest gleaming of pure red, blue, green, orange or purple, as the case 
may be; and sometimes several of these bright colors coexist in the same 
feathers, showing either separately, in different lights, or intermixed, in one 
light. But the change from one bright color to another is less characteristic 
of himimingbirds' iridescence than the change from dull black to keenest 
brightness. It is in the fullness of this change, and the extreme brilliancy 
of the high-light tints, that the supremacy of their coloration lies. Perhaps, 
after all, they do not quite deserve the palm for iridescence, in the strict sense 
of the word, but for changeable and luminously brilliant color, they are almost 
unique among animals. Indeed, they have an almost unrivaled obliterative 
equipment. Behind the dazzling, scintillating blaze of its jeweled head, how 
can the little round body of a hummingbird be seen ? That shifty blaze of 
red or green or purple light, one instant partly clouded over, and in the next 
flashing out into the sharpest sunlike sparkles, completely eclipses and masks 
the form and. solidity of the body, now veiling it, and now piercing it, so to 

103 



speak, with all manner of rents, and vistas of its brilliant, sunlit background, 
utterly bewildering to the beholder. 

It is a noteworthy fact, and an interesting theme for study, that the bright 
colors of almost all hummingbirds are only revealed, or at least only revealed 
in their full power, when the birds are seen head-on and facing into the light. 
This is true, indeed, with many other birds of changeable color, but in no 
other group is it nearly so marked as among the hummingbirds. Many of 
their brightest "beauty spots" are dead and. dusky except in full front view 
and lighting. This fact has an interesting bearing on the question of the 
special uses of hummingbirds' glorious plumage, and suggests several addi- 
tional possibilities. One of these is that their obliterative coloring is ad- 
dressed primarily to insects on the flowers and leaves before which they hover, 
and is therefore offensive rather than defensive. Hummingbirds are so small 
and lightning-swift that it must be nearly impossible for any predatory birds 
or beasts to catch them. Tree lizards and small hawks may occasionally 
seize them while they are perching, although they usually (?) sit on bare, 
isolated twigs, and are extremely watchful. This watchfulness, however, 
seems to be directed mainly against other members of their kind (i. e., other 
hummingbirds, of whatever species), and is aggressive rather than defensive. 
They are, as is well known, extraordinarily pugnacious, and where several 
congregate they are continually chasing one another. Nor is this strange 
animosity exercised solely against their own kindred; with equal frenzy they 
dart at flycatchers, hawks, eagles, — any flying bird, either big or small, that 
enters their domain. On the whole, it must be assumed that they enjoy a 
comparative freedom from the dangers that beset most of the smaller birds. 
Yet their obliterative equipment is among the finest, and must be of great im- 
portance to them. The effulgent, steely brightness of their head-colors, often 
extended outward by erectile tufts and crests, and showing only in full front 
view, undoubtedly serves to 'veil' them from the sight of insects lurking in 
and upon leaves and flowers. Without such adornment, the birds would 
loom up darkly solid between their little victims and the light, thus warning 

104 



them and giving them a moment's grace for taking flight or crawling out of 
reach. But their marvelous headgear masks their menacing solid forms. 
Irradiated, as it often is, by sunlight, it matches the bright, gaudy back- 
ground of flowers, leaves and sky, piercing and obliterating the interposed 
bird-bodies. As, from moment to moment, the bright real scene beyond 
flashes and twinkles and changes, so the mock scene on the hummingbird's 
front sparkles and shifts with his every slightest movement, and every flicker 
of the light that vivifies it.* 

It is needless to discuss here the meaning of hummingbirds' many re- 
markable appendages, inasmuch as the high obliterative value of such de- 
velopments in general has already been explained. 

Male and female hummingbirds are usually unlike in plumage, and their 
differences correspond to those of most other forest birds. Furthermore, they 
are in close and evident accord with the differences in the habits of the sexes. 
The female sits on her neat, moss-trimmed nest, in a shady place, while her 
mate is buzzing around among the flowers and sunbeams. The bodies, even 
of the males, are usually equipped with obliterative shading, and the females 
almost always have it in full development. They are dim in color', relatively to 
their mates, being mainly soft (but often metallic) green, brown, or gray, 
and rarely having any fully developed gemlike spots or plumes, — ^all of which 

* A probable minor function of this flashing headgear, under the very same conditions, is the 
illumination, by reflected light, of the calyxes of flowers, and the shaded sides of leaves, which the 
hovering hummers probe and search. They carry, as it were, little colored lanterns on their heads, 
whose disk of blue or green or red or purple light can be thrown deep into a tubxdar flower, or moved 
up and down and back and forth across a dusky leaf. When any of the very bright ones among these 
gaudy little 'reflectors' are played on by bright sunlight, and headed more or less directly sunward, 
they cast a really illuminating glow, which can scarcely fail to be of service to the hummers in their 
insect-hunting. Again, it is likely that the flaming head-dresses of these little birds — as also the erec- 
tile crests of flycatchers — sometimes act as "war paint." When a male hummer leaves his hovering 
and perching amidst flowers, where his colors are potently obliterative, and launches forth into free 
air, often above the tree-tops, in violent pursuit of another bird, his fiery-flashing brilliance may 
well cooperate with the arrowy vehemence of his attack in frightening the object of his anger. Far 
oftener, however, it must tend rather to dazzle and stupefy the persecuted bird, and, by its incessantly 
varied gleaming, to bewilder him as to the exact position of the chaser. 



is in evident harmony with their habits. For, as with other female birds, one 
of the most critical periods of their lives is the time of brooding, when, hour 
after hour and day after day, they have to sit on top of their open nests, in 
quiet, steady-lighted nooks. Even when, as is usually the case, the females 
as well as the males feed in the gay, sunlit upper border of the forest, they 
descend into the shady underworld to nest. Hence the fitness of their being 
softly colored and delicately counter shaded, while their mates are adorned 
with magnificent jewel-spots and strange appendages. In this matter hum- 
mingbirds will serve to exemplify the whole group of forest birds in which 
the sexes are decidedly unlike. The female, almost without exception, is 
colored and shaded in the way which best conceals her while she is brooding; 
whereas the male is colored for active life among the leaves and flowers. 
Corresponding sexual differences of habits and plumage occur among other 
than woodland birds. Those of ducks I have already mentioned. 



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CHAPTER XIX 

BIRDS, CONCLUDED. VARIOUSLY INVOLVED PRINCIPLES OF PROTECTIVE COL- 
ORATION OF THE BIRDS OF TROPICAL FORESTS. WINTER BIRDS OF 
THE SNOWY NORTH. CONCLUDING REMARKS ON BIRDS 

THE dim, brown underworld of tropical forests is tenanted by a race of 
birds and beasts which show a wonderful uniformity in coloration and 
degree of counter shading. The daylight in these solenm depths is diffuse 
and weak; hence the animals which live in them are as a rule very slightly 
shaded from dark to light, and many have pale-brown undersides. Brown 
is their prevailing color, and there is one particular tone of rich chestnut-brown 
which occurs almost unvaried on many hundred species. Such sameness of 
coloration is remarkable; but it is in perfect keeping with the monotony of the 
realm in which the creatures live. Almost nowhere else can one find such a wide- 
ly extended prevalence, throughout the year, of a particular degree of light and 
a few simple tones of color, as exists inside the shell of the great tropical forests. 
On the outside of that shell everything is different. There, in the blazing 
sunshine toward which the closely crowded trees and vines are ever struggling, 
the victors heave their leafy heads, flashing and dancing with a thousand tints 
of gold and green and sky-reflected blue — ^jeweled with gorgeous fruits and flow- 
ers. In this gay realm of scintillating lights and colors live almost all the bril- 
liant birds and butterflies, for which the tropics are famous; and they are as 
closely fitted to their environment in colors and patterns as are their dull-brown 
relatives of the somber shades below. The tropics are as rich in dull-colored 
birds and butterflies as in bright ones; but the dull kinds are not often collected 
and exported except by naturalists, and do not attract popular attention. 

The transition from the tree-top to the ground type, in habits and in col- 
oration, is beautifully gradual and consistent. Blue— clear, skyey blue — 

107 



plays a large part in the costumes of the true tree-top perchers. (Vide, in our 
northern American fauna, the Indigo Bunting and the Bluebird.) With it are 
combined red, green, yellow, and all the other bright colors, in sharp ruptive 
patches, picturing, in general, the sunlit forest crown seen from above. One 
step below these 'perchers in air' live the skulking tree- top birds, as it were 
the rails and gallinules of the forest's crown. These live among and beneath 
the outermost leaves, immersed in a deep bath of green light; and many, though 
not all of them, are mainly or wholly green. Such, preeminently, are the 
parrots, those queer and splendid geniuses of the tropic woods. They crawl 
about through the forest's crown, and comparatively seldom sit on bare, 
high perches. When they do so they are of course inconspicuous enough 
against the tree-tops; but many of them lack the finer developments of sky- 
matching and more generalized background-matching costume. Instead 
they are attired to match the leaves and flowers among which they are feed- 
ing. They are obliteratively shaded, almost all of them, but faintly, in keep- 
ing with the diffuseness of their usual leaf-dimmed illumination, and their 
acrobatic feeding-habits, which put them into all sorts of irregular positions 
relative to the sky-light. There is almost certainly a significant connection, 
too, between their habit of feeding head-downward, and their gayly blossom- 
colored tails. Poked up above the feeding parrot's line of watchfulness, and 
often into the stratum of gaudy flowers and fruits, this tail must have the 
best possible disguise if its owner is not to be pounced upon from above by 
some swift hawk. So it is done out into brilliantly disruptive and oblitera- 
tive spots and patches of rich flower- and fruit- and sky- and sunlit- foliage- 
colors, — "conspicuously ornamented," as people used to say. In fact, it is 
doubtless, under the normal, appropriate conditions, a very mask of masks. 
Fitly colored for inconspicuousness above the 'green-bath' region, it is 
scarcely less so for the midmost recesses of that region itself, because the all- 
suffusing greenness greatly dims the brightest contrasting hues, bringing the 
red, yellow or purple patches of a gaudy-motley bird nearly or quite into 
unison with the variations of interior vegetation colors. Thus it is not strange 

io8 



that some of the typically 'skulking' tree-top haunters of the tropics are 
most gaudily 'patched,' more so even than the parrots, and that many of 
the brightest colored 'high-perchers' spend much time fairly amid the foli- 
age. But pure leaf-green is the prevailing color of the tree-top foliage haunt- 
ers, just as rich brown is that of the forest ground birds. Between these two 
types again there are perfect intermediates. Such is the motmot, with its 
ground-brown underside, its soft green back, and its black and bright-blue 
head; such also is the beautiful jacamar, described in Chapter XVI (p. 
90), and such are some of the dim-colored, low-ranging hummingbirds. 
The toucans, also, with their great amount of sharply defined black, are best 
fitted for obliteration in the intermediate woodland realms, where darkly 
shadowed big branches and tree trunks contrast with sun-spots and gay vis- 
tas. But they are also tree-top birds, high-perchers, and their vividly patched 
costumes of course stand them in good stead in these situations also, in spite 
of the redundant black. This usually covers the head, back, wings and 
tail; while the underside is marked with big patches of bright color — ^red, 
orange, yellow, white — sometimes all four together — ^more or less blended into 
one another, but ending sharply against the black. The huge but almost 
weightless bill also is brilliantly adorned with yellow, white, or flaming orange, 
in bold bands and stripes, and the naked skin around the eye is usually 
bright colored — ^blue-purple, peacock-blue, or green. Truly, toucans are 
gorgeous birds! But it by no means follows that they are conspicuous in 
their native woods! Not even though they are vociferous and active, and 
often alight on exposed tree-top perches. Here or lower down in the forest, 
their gaudy 'ruptive' patterns 'break them all to pieces,' and though the 
predator at whose approach they 'freeze' into rigid stillness may espy the 
black piece, or the red piece, or the yellow or the blue piece, he is still far 
from sure to recognize his quarry, for none of these pieces has the form of a 
bird. So with the colors of the tanagers, the birds of paradise, the macaws, 
and all the rest of the brilliantly pied tropical forest birds, many of which 
range, like the toucans, from the upper border of the forest underworld to 

109 



the airy tree-tops. The frequent black in their costumes, though it often 
fits in very well with their tree-top background-picturing and 'ruptive' pat- 
terns, seems on the whole to be a concession to the time they spend among 
dark trunks and branches fairly within the forest. Practically all these party- 
colored tropical birds have counter shading, in the main relations of their 
colors, however much its smooth gradation is broken and interrupted by the 
bold patterns, and however irregular and acrobatic may be their feeding- 
postures. The multiplicity and variety of bright-colored vegetable forms in 
the sunlit crown of a tropical forest make a great variety of 'ruptive' pat- 
terns and colors effective for the disguisement of its birds. As has been told 
in an earlier chapter, ruptive patterns are often intricately commingled both 
with iridescence and with appendages, all three factors working toward the 
one end, 'obliteration.' It is in the tropics, — in the tree-tops and in the forest- 
borders — that we find the highest development of all three principles, both 
separate and combined. Iridescence is not second in importance to ruptive 
pattern, nor is it less widely and variously used. Appendages also play a 
very important part, as we have shown. 

One more component principle of 'ruptive' coloration, prominent in the 
costumes of tropical wood-birds, must be here explained. This is the fre- 
quent juxtaposition of complementary colors. Just as brilliant iridescence 
tends to range from one color to its full opposite, or "complementary" — as 
from red to green — so, when two bright colors occur side by side in a ruptive 
pattern, they are usually not kindred, but complementary. Thus we find 
green-breasted trogons with red bellies, purplish-blue-breasted trogons with 
orange bellies, orange-yellow tanagers with steel-purple backs, and so oh. 
Not only are the colors thus placed intensified by mutual contrast, but, by the 
very added sharpness of their difference, the ' disruptive ' effect is heightened. 
The opposed patches seem less than ever to belong to one and the same ob- 
ject. A bright color tends even to create its complementary.* Look at a 
rich yellow flower, or some other small yellow object, against white paper. 

* See the footnote on p. 19, Chapter I. 
no 



The white next the yellow seems to glow with purple, yellow's opposite. By 
the same token, two actual complementary colors side by side are much more 
powerfully brilliant than two kindred ones so placed. This law has yet other 
bearings on our present subject. It tends to explain the otherwise somewhat 
anomalous bright red of certain strictly foliage-haunting birds, like the sev- 
eral tanagers and trogons. How can such birds, living almost always among 
green leaves, in a bath of green light, profit by wearing the most vivid red, the 
diametric opposite of foliage-color? The answer, in part, is this: dimmed 
by the strong bath of green light, the bird's red, actually brilliant, looks barely 
brighter than many of the glowing brown interstices, the paler shadows on 
dead leaves, twigs and tree trunks amidst the verdant foliage. Even brown 
dead leaves most favorably situated for showing off their color amidst live foli- 
age are brighter than bright-red tanagers or trogons least favorably situated 
for display against a like background. Also, there are, commonly, many dis- 
eased leaves amid the foliage with red as bright as the birds'. But there is no 
denying the fact that some of these birds, for instance the northern Scarlet 
Tanager, are more conspicuous in the green woods than their foliage-colored 
kindred. On the other hand, again, it is true that bright, strongly contrasted 
hues, and red among the rest, well serve to produce 'ruptive' effects in the 
color-neutralizing, deeply green-steeped light of the leafy lab)Tinth in which 
such birds live, where dimmer tints could not hold their own. This is the way 
with the beautiful red-and-green trogons, which are by no means easy to dis- 
cover in their native woods, though vociferous and tame. In tropical as in 
temperate woodlands, however, the smaller gleaning birds and flycatchers of 
the shaded lower leafage are characteristically green and yellow and olive, 
without very bold markings. They live fairly hidden amidst shaded foliage, so 
that dim leaves in a near view, undiversified by other landscape-details, form 
their normal background. In his admirable paper on the birds of Trinidad, 
at the mouth of the Orinoco River,* Mr. F. M. Chapman, the American nat- 

* "On the Birds of the Island of Trinidad," BvUIetin of the American Museum of Natural His- 
tory, vol. vi, 1894. 

Ill 



uralist, has two pages of very interesting discourse on the color relation be- 
tween birds and their surroundings in the wild-woods of that island. He 
fully saw and described the distinctness of the three main color-classes of trop- 
ical forest birds, the brown, the green, and the gaudy-motley, each with its 
own appropriate local habitat. Much of what I have said on this immediate 
theme is scarcely more than an echo of Mr. Chapman's words, though based 
on our own subsequent investigations in the same island forests. Limited as 
they are in extent, the primeval woods of Trinidad are doubtless fairly repre- 
sentative in character of the great South American tropical forests, and, by 
the same token, of all the humid tropical forests of the world. For, as we 
learn from traveled naturalists, tropical "high woods" are all much alike in 
their main general characteristics. Just how largely this likeness extends to 
the general habits and disguising-equipments of the forest birds, we, person- 
ally, cannot say; but there is every reason to suppose that the main principles 
are the same among the birds of tropical Asia, Africa, and Malaysia, as among 
those of tropical America. Indeed, a study of tropical birds in museums, and 
of the writings of naturalist travelers, leaves one with little doubt on this 
score. 

In the matter of local habitat, Chapman divides the forest birds of 
Trinidad (and hence of all tropical America) into five groups, namely, those 
of the tree-tops, those of the shaded foliage below the tree-tops, those of 
the tree trunks below the foliage, those of the bushes and scrub at the for- 
est's border, and those of the ground. The first and second groups comprise 
respectively the gaudy and the green birds, as has been told. The three 
remaining groups Chapman lumps as brown birds. This will do for a very 
general classification, but it seems to me that while the scansorial and ter- 
restrial species may well be classed together, the scrub birds should be sep- 
arated from them. For, many of these scrub-birds, as Chapman intimates, 
lack the characteristic forest brown, or have in addition a large share of other 
colors. Their 'class,' however, is laxer and more irregular than the rest, 
and its special characters are harder to define. Both in habits and in colora- 

112 



tion, its species grade into other classes, not only of forest birds, but of the 
birds of the open land, the reed swamps, bush swamps, and river banks, where 
still other systems of coloration come into play. Thus there are 'brush- 
birds' which have also a liking for spots of bare, open ground, and have ac- 
quired markings much like those of larks and other field birds of the North, 
Characteristically, however, they are somewhat boldly mottled, with much 
black and white and ash color; 'pictures' (to be seen in the dim light of the in- 
teriors of bushes) of sky vistas overlaced with obstructing, shadowed leaves 
and branches. Some of those which frequent river banks, like certain Ant- 
birds of South America, are often marked with the water-shine punctations 
described in Chapter XI, on a ground-color of muddy gray or brown, oblit- 
eratively shaded. But the vagaries of this none too sharply defined class 
cannot be described in detail here. The species which constitute it are less 
typically birds of the forest than of the brush-lands outside the forest. Nor 
are they, as a color-class, peculiarly characteristic of the tropics, being scarcely 
separable from the brush-birds of temperate climes. True, the brown, green 
and gaudy classes are also represented in northern woodlands, but by no 
means in such full and special development as they have attained in the teem- 
ing tropics. 

In the snowy northern winter, on the other hand, where the avifauna is 
extremely meager, we see special color-adaptation reduced to its simplest 
terms. The costumes of the few birds which pass the winter in the snowy 
northern, forests, deciduous or evergreen, are, it is evident, specially fitted 
to that season of the year. Some of these birds even, like several of the boreal 
mammals, turn white at the approach of winter, resuming their gray or brown 
mottled plumage in the spring. Such are the ptarmigans, described in Chap- 
ter VII. But most of the species either keep the same coloration throughout 
the year, or merely become somewhat paler and dimmer in the autumn, grad- 
ually brightening, by the erosion of the feather-tips, through the winter and 
spring. But even those which do not change color are best equipped for con- 
cealment in the winter — the dangerous time of leafless woods and keenly 

"3 



hungry birds and beasts of prey. One of the most patent signs of this is the 
great prevalence of white in their costumes. The Snowy Owl, for instance, 
the chief rapacious bird of the high north, is white (more or less profusely 
flecked or barred with sooty brown) throughout the year. During the few 
weeks of arctic summer, when it hunts and nests on mossy, treeless tundras 
or barrens, it must be a conspicuous object when seen from above against 
the ground (although even then it may often be mistaken for a scrap of lin- 
gering snow or ice). But it has little or nothing to fear from predaceous 
enemies, and its summer diet consists chiefly of lemmings and other small 
mammals which live on the open ground, so that the owl always appears 
above them, against the sky; hence white serves it as it serves the seafaring 
terns and gulls (Chapter XII) and the partly white-masked mammals to 
be described in a later chapter. Another northern bird, colored almost 
exactly like the Snowy Owl, and with kindred habits, is the White Gerfal- 
con. In addition to these more or less predominantly white birds (ptar- 
migans, owls, and falcons), many of the smaller species of the winter North 
are largely marked with white (irrespective of their obliterative white under- 
sides). Noteworthy among these are the woodpeckers, titmice, some of the 
Fringillidce, and two or three of the CorvidcE (namely, the magpies and the 
North American Blue Jay). Most of them wear a pied or boldly speckled 
pattern of black and white, which reaches its highest development on some 
of the woodpeckers, as the Hairy and Downy {Dryohates villosus and D. 
pubescens) of America, and the Great-spotted and White-backed {Picus 
major and P. leuconotus) of Europe. These woodpeckers are in fact cov- 
ered with adequate generalized pictures of bits of winter landscape, where 
dark tree trunks and branches relieve against the snow or sky. Fig. 83 
(photographed from a picture made by combining a real Hairy Woodpecker's 
skin with a painting of a winter-forest landscape) will tell the reader more than 
many words. Even in summer, though less wonderfully fitted to the land- 
scape, these woodpeckers are far from being conspicuous birds. The larger 
outstanding spots of white still often pass for, glints of sky seen through the 

114 




Fig. 83. Hairy Woodpecker (Dryobates villosiis) in winter woods. [See p. 114, Chap. XIX.] Pliotosrapli 
of a stuffed skin against a painted landscape. Scene copied, 'tone' for 'tone,' not from the woods, but from the 
woodpecker. The reader must judge for himself as to its realism. 



forest, while the smaller ones, and under some conditions the larger ones too, 
produce a mottled effect much like that of the tree trunks on which the birds 
climb. (See Chapter VIII, p. 50.) Significant in connection with the evident 
winter-picturing in the costumes of these northern woodpeckers is the differ- 
ent coloration of their southern relatives. The Downy and Hairy Wood- 
peckers are distributed from the southern United States almost to the northern 
limit of tree-growth, and being non-migratory, have developed certain geo- 
graphical racial differences. The birds of the northernmost race are biggest 
and whitest, those of the southernmost, smallest and blackest. Other species 
of the same genus, and of nearly allied genera, which are peculiar to the 
southern part of the country, below the limit of snow, lack the larger white 
blotches, being for the most part closely barred and speckled, in 'tree-bark 
patterns.' The Golden-winged Woodpecker (Colaptes auratus, etc.), which 
is mainly brown and black and yellow, abounds in the northeastern United 
States during the summer, but migrates southward in the fall, for the most 
part keeping outside the snow-line. Looking still farther south, to the Amer- 
ican tropics, we find the woodpeckers brown and red and yellow and gray 
and olive, and, with a few exceptions, almost entirely devoid of white. Many 
of the tropical woodpeckers, indeed, and their allies in habits the Wood Creep- 
ers (Dertdrocolaptidce), belong strictly to the class of tropical 'brown birds' 
described earlier in this chapter. 

The northern tits and nuthatches are colored much like the northern 
woodpeckers, but in simple, bold, undiversified 'ruptive' patterns. (See 
Fig. 61.) So also with the magpies, which have the added gift of rich irides- 
cent color in the tail and wings,— picturing snow-shadows and fir foliage. 

The costume of the beautiful Blue Jay (Cyanocitta cristata) is a wonderful 
picture of a winter landscape — snow in shadow, snow in sunlight, sky, trees, 
and vinous-gray scrub — all are there, in true and exquisite comminglement. 
Here again we have a picture to show in aid of unconvincing words. The 
Blue Jay picture in Plate VI, unlike the woodpecker figure, was painted 
from bird-skins against a real out-door background. Of course the Blue 



Jay's costume is not confined to this one kind of background-matching. It 
pictures, perhaps equally well, a much nearer bit of snowy ground, thickly 
fretted with blue shadows, with some dark twigs or branches relieving against 
it. Wherever the bird alights in the winter woods, he looks like a vista through 
the tree in which he sits to one or another of these blue and snow-bright back- 
grounds. He bears a full obliterative shading (from dark blue and black to 
white), without which the delicate distance-picturing would be impossible. In 
summer the Blue Jay's perennially unchanged coloration is less closely fitted 
to its environment; but the bird is never conspicuous. The blue, seen in 
the leafy sylvan dimness, is usually soft and dull, and not sharply differen- 
tiated from the vinous ash-color of the breast and flanks; the white spots, as 
in all such cases, picture glints of sky, or lighter leaf-vistas; while the dark 
marks look like sticks and twigs and holes and shadows. (See Fig. 60.) Or 
again, when the clear, light blue of tail or wings gleams out with especial 
brightness, it may pass either for sky-shine on the leaves or for a bit of blue 
sky showing between them. Another boreal winter bird, the American Gos- 
hawk, in adult plumage, wears a beautiful combination of the color of bare 
twigs and deeply shadowed snow; and the nuthatches also have the same snow- 
shadow color on their backs. 

Among the Fringillidcs, the best example of a white-marked northern bird 
is the Snow Bunting {Passerina nivalis), common to both continents. Some 
of the redpoll linnets (Acanihis) have much white in their make-up (though 
mixed and blended rather than in clean spots). Some of the crossbills, and 
the pine grosbeaks, also have a share of it. But with most of the northern 
conivorous and bud-eating fringilline birds, red plays an important part, in 
the winter as well as in the summer plumage. For what are the chief colors 
of field and forest landscape in the northern winter? Three of them, black 
and white and blue, have already been named; what are the others? Soft 
red, gray (of tree trunks), and dusky green. Vinous ash-color ranging fairly 
into red is the hue of one large and ubiquitous element of these winter scenes, 
namely, the outer twigs of all the deciduous trees and bushes, covered with 

116 



buds. (See Plate VI again.) Except when a wet snowstorm or an icestorm 
has plastered and veiled these twigs, the average northern landscape in win- 
ter is full of great masses of soft, purplish red, reaching here and there a 
brighter tint. Golden brown, varying to red and purple, is also the color of 
the cones of spruce and pine and fir trees. It is among these pink and bronzy 
twigs and buds, seed tassels and cones, that the northern grosbeaks, linnets, 
and crossbills get their food, and the red or reddish colors worn by many of 
them are therefore in full accord with their environment. So it is also that 
the red spots on the heads of the males of northern woodpeckers are not dis- 
cordant notes in their obliterative pattern. 

Female crossbills and pine grosbeaks are olive-green, olive-yellow and 
gray — the colors of tree trunks and the foliage of evergreen conifers, and 
many of the cones themselves. 

The coloration of some of these birds, notably the Red Crossbills, some- 
times helps to produce a truly mimetic effect. In conformity with their acro- 
batic habits of topsy-turvy climbing and feeding, these crossbills have a very 
scant obliterative shading. In a full, unbroken light their solidity is therefore 
apt to show, and when they sit or cling on coniferous trees they often look 
much like cones, by virtue of their similar colors and not dissimilar shape. 

Once more we must return to the subject of obliterative white markings 
on birds' upper sides. The birds that wear them may be grouped as follows: 
those that live high enough up in trees or bushes so that glints of sky and 
gleaming foliage- vistas are common factors of their background; those that 
live on the water or the borders of water, where reflected glints of sky are com- 
mon; and, last but not least, those which live amid snow. Predatory birds 
that are mainly white all over, like many sea birds and the Snowy Owl, are, 
as we have shown, equipped for the greatest possible elusiveness when seen 
against the luminous sky by animals beneath them. The application of this 
principle among mammals we shall describe in a later chapter. Its bearing 
on the coloration of birds alone is large, far larger than one would at first 
suppose. It is involved, for instance, in such cases as those of the snow- 

117 



white herons, egrets and swans, whose whiteness tends to efface them against 
the sky, in the view of their aquatic prey and enemies, as no other color or sys- 
tem of colors could. Outside of the several classes above named, which 
means among ground birds and birds of the interior forest gloom, white mark- 
ings are practically wanting, with the exception of those that belong purely 
and simply to obliterative shading, and the occasional white tail-spots, dis- 
played chiefly in flight, which we shall consider in a later chapter. 

The foregoing nineteen chapters together form an exposition, however 
fragmentary, of all the main laws of disguising-coloration as applied to birds, 
in as far as they have yet been discerned by my father. In truth, although 
we have disclosed much that is new, even in addition to the big general prin- 
ciples of obliterative shading and picture-pattern, yet the subject is no more 
than broached. 

For several reasons we have seen fit to treat of birds in more detail than 
we shall attempt with other classes of animals. In the first place, birds- are 
ahead of all other classes, with the doubtful exceptions of fishes and lepidop- 
terous insects, in the elaborate variety and extreme development of their dis- 
guising-coloration. (The slender, simple hairs of mammals, for instance, are 
but a paltry medium for the building up of patterns, relative to the broad, flat 
and subtile feathers with which birds are covered.) In the second place we, 
personally, know more about birds than about any other animals. In the 
third and last place, the main principles of disguising-coloration are the same 
throughout the animal kingdom, and therefore if one describes them some- 
what minutely in connection with one representative class, the other classes 
can be dismissed a great deal more briefly. 

The next three chapters will deal with mammals. 



ii8 



PLATE VII 




r4 brCO.'OMn'IMORB . 



BXPLANATION OF PLATE VII 



COTTONTAIL RABBIT. 

Painted by. Gerald H. Thayer. Background mainly by Emma B. Thayer and A. H. Thayer 



CHAPTER XX 

MAMMALS. GENERAL PRINCIPLES OF THEIR DISGUISING-COLORATION. FULL 
OBLITERATIVE SHADING ALMOST UNIVERSAL AMONG THEM. EXCEPTIONS 
CONSIDERED 

ALMOST all mammals, from some of the biggest oceanic cetaceans to 
-^ *■ the smallest terrestrial quadrupeds, are equipped with a full obliterative 
shading of surface-colors. That is, they are darkest on the back and lightest 
on the belly, usually with connecting intermediate shades. White is by far 
the commonest color for the middles of their undersides, while the dark of 
the upper sides very often culminates in a black or dusky median line, a sort 
of painted 'ridge pole,' laid along the center of the back, over the tips of the 
dorsal vertebrae. With or without such extreme accentuation, complete ob- 
literative shading characterizes most of the species of almost all the mam- 
malian orders. This generalization applies to the great order Marsupialia, 
comprising the kangaroos, opossums, phalangers, the Tasmanian wolf, and 
many other forms; to the marine order Cetacea (whales, dolphins, porpoises, 
etc.); to the order Chiroptera, or bats; to the vast order Rodentia, including 
rats, mice, squirrels, beavfers, hares, agoutis, porcupines, etc.; to the order 
Insectivora (hedgehogs, shrews, moles, etc.); to the order Ungulata (hoofed 
animals, among which we may here include, for convenience, the elephants 
and the hyrax, as well as the tapirs, rhinoceroses, and the hippopotami) ; to 
the great order Camivora (containing the cats, from the lion to the lynx, the 
civets, mongooses, and hyenas; the canine beasts — dogs, wolves, jackals, 
foxes, etc.; the otters, weasels, raccoons, badgers, bears; the sea lions, wal- 
ruses and seals) ; and to the order Primates., including lemurs, monkeys, apes 
and man. But in all the above-named orders, and notably in Ungulata, Chir- 
optera, and Primates, there are exceptions to the rule. These exceptions are 

119 



most significant, since, in almost every case, they accompany some important 
peculiarity in the animal's habits or physical characteristics. In the cos- 
tumes of many bats, for instance, the counter shading is defective, or alto- 
gether lacking, the fur of the lower surface being almost or quite as dark as 
that of the upper. But this is in strictest keeping with their habits, for they 
are nocturnal and volant, flying swiftly, and for the most part feeding on the 
wing, like goatsuckers, while, unlike goatsuckers, they sleep by day in the 
pitchy darkness of deep caves and ruins, or in hollow trees, suspended by their 
hind claws, and hanging head downward, perpendicularly. Hence, it ap- 
pears. Nature has been very little concerned with giving them disguising 
coloration. Their perpendicular sleeping-posture in itself precludes the pos- 
sibility of their benefiting by the regulation obliterative shading while they 
are at rest. If they are to be counter shaded at all, it must be from tail to 
head, rather than from back to belly. Traces of such an aberrant shading 
exist on many species, in the shape of white or yellowish markings on the 
face,* and a brown paler than that of the rump and belly on the fore-back 
and fore-breast. This partial counter shading, as well as bats' prevailing 
earthy and rock-brown color, serves them in the cases where their roosts are 
more or less exposed to the daylight. Some kinds, indeed, habitually roost 
in the open air, under big tropical leaves, under the branches of trees, and 
on their trunks. The tree-trunk species while roosting are lighted as are 
scansorial birds, and for obliteration they would have to be counter shaded 
in the normal way, — as some of them are. But several of these open-air bats 
are developed for mimicry instead of obliteration. Thus a beautiful little 
South American species is formed, marked and colored to look like a woody 
knot or other excrescence on the underside of a mangrove branch, whereto it 
clings, by day; not hanging downward, but pressed close against the bark, 
holding on both with feet and finger-hooks. Usually several are found to- 
gether, in a neatly distributed little group. Disturbed, they take wing all 
together, with a tiny, complaining twitter, and fly away like a troop of sand- 

* See also Chapter XXII, p. 157. 
120 



pipers; alighting again, daintily and quickly, on the first new branch that 
suits them, — or sometimes wheeling and returning to their former perch, — and 
instantly they are changed back into lifeless knots. 

When a normal obliterative shading does exist on bats, as is the case with 
a good many species, its main service is probably the making them addition- 
ally elusive in their crepuscular and nocturnal flights. The shading is usually 
rather slight, from deep brown to paler grayish, but it sometimes reaches 
dingy or even pure white. 

There is no other important order of manmials in which obliterative shad- 
ing and disguising coloration in general play so small a part. The compara- 
tively few other beasts whose costumes are notable for their nonconformity 
with the predominant rules of obliterative coloration, may be grouped as fol- 
lows: They are either strictly nocturnal (some of the smaller camivora, and also 
some beasts which are large and fearless, but only semi-predaceous, e. g., many 
bears), or fossorial, living almost wholly underground (some edentates and 
moles), or arboreal, skulking (wont to take refuge in thick coverts and dense 
shade), and also acrobatic, often standing erect, and thus exposing their un- 
dersides to full light (e. g., some of the apes and monkeys), or protected by 
some extraordinary defensive equipment, so that they are in little or no dan- 
ger from the attacks of predatory creatures (e. g., hedgehogs, porcupines, 
echidnas, pangolins, and some armadillos), or they enjoy a like security by 
virtue of their gigantic bigness, and, being herbivorous, have no need of ob- 
literative coloration to aid them in securing their food (e. g., elephants, rhi- 
noceroses, and hippopotami). Compared with the vast roll of the species 
equipped with full obliterative shading, the exceptions contained in these five 
classes are numerically insignificant. But they are important as bearing 
further weighty witness to the beautiful completeness of the correlation be- 
tween animals' modes of life, defensive and offensive armaments, and dis- 
guising-coloration. The hedgehogs, porcupines, and echidnas (belonging 
respectively, in the sequence named, to the orders Insectivora and Rodentia 
and the order Monotremata of the strange subclass Ornithodelphia) are all 

121 



equipped with a thick coat of formidable spines, but have no obliterative 
shading, nor any other pronounced elements of concealing-coloration; whereas 
their closest relatives which lack the peculiar defensive armaments are all 
(if we set aside a few fossorial forms) obliteratively colored to the full. The 
echidna's sole known ally, Ornithorhynchus paradoxus, the Duck-billed Plat- 
ypus, has no spiny mantle, but its brown furry covering is obliteratively shaded. 
So also with the coypou, beaver, and other rodents more or less closely allied 
to porcupines, and with all the spineless Insectivora akin to hedgehogs, with 
the possible exception of a few of those which live in dark tunnels under- 
ground, namely, moles and shrews. But the most strictly fossorial shrews, 
and even moles, must sometimes come out into the daylight, where they are 
exposed to the attacks of predaceous birds and beasts; and accordingly we 
find some degree of obliterative shading in the coats of almost all the species. 
There may be some kinds which are as dark on the belly as on the back; but 
not one of the most monochrome-looking species we have examined has proved 
to be so. 

Among apes and monkeys, the want of pronounced counter shading is by 
no means uncommon, though it does not characterize the majority of species. 
This lack may be fully seen on the big anthropoid, semi-erect apes, the scrawny 
hair of whose breasts and bellies is as dark as that of their backs. But, 
thanks to their size and strength and ferocity, these great apes belong in part 
to the class of 'immune' beasts, while they also lack the need of obliterative 
coloration for offense which the truly rapacious animals have. The Orang- 
outan of Borneo is described as being the king of its native jungles, dreading 
only man; and we may well assume that the huge gorilla of central Africa 
enjoys equal privileges. 

It might be supposed that whales were sufficiently protected by their 
colossal size and strength, and that the toothless kinds, which feed on 
the minute, lowly animal organisms that swarm in the ocean like dust 
motes in house air, would have no possible need of any kind of disguising- 
coloration. Yet almost all of them have a fully developed obliterative shad- 

122 



ing * and almost all are subject to dangerous and deadly attacks from smaller 
marine animals,— ^uch for instance as the Grampus or Killer {Orca gladiator). 

Sea-cows or manatees, and dugongs (order Sirenia), those uncouth sur- 
vivors of an ancient race of littoral-marine and fiuviatile herbivorous mam- 
mals, are not pronouncedly equipped with obliterative shading. They are 
colored like grayish mud and dingy water, however, and tend to be palest 
underneath. 

The predatoi-y and semi-predatory land beasts which nearly or quite lack 
obliterative shading are few in number, and, as has been said, they are chiefly 
nocturnal.t Almost all belong to the group Arctoidea, or bearlike animals. 
Good examples are the black and brown bears of Europe and America, the 
Polar Bears {Ursus marUimus) the Wolverine {Gvlo luscus), and several ex- 
clusively American beasts, the skunks {Mephitis and Conepatus), and the 
Fisher or Pennant's Martin {Mustela pennanti). But, though largely without 
counter shading, some of these animals are obliteratively colored to a high de- 
gree. The Polar Bear, like the boreal foxes, hares, weasels and ptarmigans 
in their winter dress, is immaculate white, above and below; and, as has been 
explained in connection with ptarmigans (Chapter VII), this uniform white- 
ness is about the nearest approach to perfect obliterative coloration that an 
inhabitant of realms of glaring snow and ice can have, because there the 
monotonous, perfect whiteness makes counter shading inadmissible, since 
it would involve making the beast's top darker than the surrounding 
scene. J The shadowed and therefore too dark underside cannot be light- 
ened, but neither must the fitly illuminated white back be darkened to 
match it, for then there would be a monochrome, complete (although flat- 
seeming) beast-form to silhouette against the background. The skunks, 
and in less degree the wolverine, are equipped with wonderfully efficient 

* Those whales which prey, more or less, on forms that have both sight and power of locomotion, 
must be quite as much hel{)ed by obliterative coloration in their approach to such prey, as any of the 
beautifully counter shaded fishes that hunt in the same waters. — A. H. T. 

• t The slight counter shading of black nocturnal animals has apparently the exact degree to defeat 
the very small illumination of night. — A. H. T. % See also p. 151. 

123 



ruptive patterns, of a peculiar sort, whose function will be explained in a 
later chapter. The other animals above named — ^brown and black bears 
and Pennant's Martin — are all nocturnal. The bears, furthermore, are too 
big and powerful to need defensive coloration; though, being partially rapa- 
cious, they do not wholly lack disguising-patterns. (See Chapter XXII.) 
Thus only the cases of the Fisher and a few other small carnivorous quad- 
rupeds of like coloration remain in any degree anomalous, while the facts that 
such beasts are nocturnal, acrobatic, and deep-forest haunting, go far toward 
clearing up the difficulty. 

The living members of that strange agglomeration of animals usually 
grouped by naturalists in the order Edentata, are almost all nocturnal, al- 
though they show otherwise great diversity of habits. Some are fossorial, 
some terrestrial; others semi-arboreal; others again, arboreal; and still others 
ultra-arboreal, being, alone among living mammals, practically incapable of 
any mode of progression except handing themselves, belly-uppermost, along 
the undersides of tree-boughs and vines. Of course I refer now to the sloths, 
Bradypodida. Their protective coloration is probably, mimetic, in part at 
least, like that of certain bats, already mentioned. To be sure, they are often 
equipped with a slight inverted counter shading (from darker bellies to lighter 
backs, as in the case of many of the lepidopterous larvae which feed and rest 
upside down); and their coloration often inclines also toward the 'ruptive,' 
based on bold, arbitrary patchiness. But these equipments are irregular 
and inconstant, and rarely or never would they appear to be of dominant im- 
portance. On the other hand, many travelers have commented on the mimetic 
function of sloths' queer, weedy-furred coats, aided by their shapelessness and 
sluggish habits; and such is very probably their chief protection. Hanging, 
lumplike, up among the complex, tangled forms of branch and leaf and vine 
and vegetable parasite, their rotundity perhaps revealed by the insufficiency 
of their counter shading, and at the same time obscured by their irregular, 
shaggy coats, they may well be hard to detect as animate forms. For they 
must look very much like masses of moss, withered air-plants, or other vegetable 

124 



debris, or like parts of moss-draped or ragged-barked boughs or trunks. So 
travelers have said, and in this case there seems to be no reason to question 
their interpretation. Sloths vary widely in color, but a rich olive-brown is 
perhaps the most characteristic tint. Sometimes they are almost green, owing 
to a growth of minute algae on their fur; and this of course enhances the mimetic 
effect, allying them in the very ingredients of their superficial structure to the 
vegetable masses all about them. Again, they are sometimes rather brightly 
varied with patches of dark brown, blackish, dull orange and yellow, and even 
white; but these markings barely attain the rank of true 'ruptive' patterns. 
One marking, however, to which they are very prone, is extremely interesting 
and noteworthy. This is the blackish stripe or spot on the fore-back, sur- 
rounded by a rim of light color, varying from orange brown to white. Strangely 
enough, this marking is almost precisely duplicated on the head of a species 
of sphinx-moth larva (see Plate XV, Fig. T, Chapter XXV) and it there plays 
an important and unmistakable part in the imitation, beautifully achieved by 
the aspect of the entire caterpillar, of a pendant, curled-up, brown dead leaf. 
The larva hangs head downward, and its white-rimmed black spot pictures 
the shadowed hole at the tip of the pendant leaf -roll. There seems very little 
room for doubt that a like effect is achieved by the peculiar shoulder-spot of 
the sloth. Evidently, this simulates a shadowed orifice, with brightly con- 
trasting outward rim, in the bottom of the vegetable mass mimicked by the 
entire beast. (See also page 157 of Chapter XXII, and Fig. 120.) 

The armadillos {DasypodidcB), another family of edentates, are terrestrial 
and fossorial, and almost hairless. But they are partially protected from 
their enemies by a hard, annulated shell, as well as by their prodigious dig- 
ging-powers. Some species roll up into almost invulnerable balls, as do 
their African and Asiatic relatives, the armor-scaled pangolins (Manidce). 
Both these families, besides being chiefly nocturnal, belong perhaps to the 
group of specially protected animals (although their armament is purely and 
passively defensive, like that of tortoises, and unlike that of porcupines), and 
their protective coloration accordingly is meager and irregular. Armadillos 

125 



are earth- and sand-colored above, and their broad, shelly roof, somewhat 
counter shaded, extends so far down over the sides as almost wholly to hide 
the shieldless and more or less hairy under parts, which, in conformity with 
the common law, are often decidedly paler in color. It is doubtful, though, 
whether the ventral paleness has in this case much significance beyond the lax 
and aborted pigmentation of a surface almost never exposed to view. But 
armadillos' heads and tails are always (?) counter shaded. 

The Myrmecophagid(B, or American Ant-eaters, are all fully furred, and, 
despite their nocturnal habits, obliteratively colored. Only three species are 
known, namely, the Great Ant-eater {Myrmecophaga juhata), the middle- 
sized Tamandua (Tamandua tetradactyla), and the Little Ant-eater (Cyclo- 
thurus didactylus). Myrmecophaga is strictly terrestrial, but does not burrow; 
Tamandua is chiefly arboreal, and Cydothurus strictly so, being haKway to 
the sloths in habits and demeanor. The two larger kinds lack diurnal ob- 
literative shading, but are equipped with powerful ruptive patterns of black, 
white and gray.* The exquisite, pale-brown furry coat of the little Cydo- 
thurus bears a rather faint obliterative shading, and a blackish 'secant' stripe 
along the underside. 

The "Aard-vark" of South Africa (family Orycteropodidce) represents the 
only other type of edentate that remains to be considered. It is strictly noc- 
turnal, fossorial (living in deep burrows), and extremely timid and wary. Its 
body is scantily clothed with coarse brownish hair, and has in all probability 
the regular slight 'nocturnal' counter shading. (See the second footnote on 
page 123.) 

I have already named the general rules which seem to govern these va- 
rious breaks in the prevalence of full-blown obliterative coloration among 
mammals. To recapitulate, the exceptions occur, in the first place, among 
beasts that are habitually or very frequently hidden away from the light, 
either underground, in caves or hollow trees, in thick vegetation, or in the 
cloak of night. In the second place, they occur among beasts, mostly non- 

* See Chapter XXII, p. 149. 
126 



predaceous, which are almost or quite inunune from danger at the hands of 
their wild fellow-creatures, by virtue either of their great size and strength, 
or of a potent fixed defensive armament. In the third and last place, a few 
defenseless arboreal mammals are equipped for mimicry rather than oblit- 
eration. 

It is, then, among unarmed, daylight-inhabiting mammals, and among 
the purely rapacious manamals, both of the plains and of the forest, that ob- 
literative coloration, based on full and simple obliterative shading, reaches 
its highest and most uniform development. Many of the terrestrial beasts, 
particularly those of the open country, are equipped with full counter shading 
and 'ground '-color alone, almost or quite without markings. Such are lions, 
wolves, jackals, kangaroos, hares and rabbits; marmots, some gophers, and 
several smaller rodents and marsupials; as well as many of the big ungulates 
or ruminants, such as wild asses, some wild bovines, and many deer and 
antelopes. It has long been known that the animals of the desert are ex- 
tremely alike in coloration — insects, reptiles, birds and mammals all sharing 
the same sandy brown. But coordinate with this fact is one hitherto ignored, 
namely, that the colors of these desert animals do as universally and unvary- 
ingly constitute a perfect obliterative gradation of shades, from dark above 
to light below. As there is great monotony and uniformity in the animals' 
lighting and backgrounds, so is there sameness in their color-tints, in their 
all-essential obliterative shading, and in their scanty pattern, — ^when patterns 
occur, for they are often wholly wanting. Among the simply-colored mam- 
mals named above, the lion and the jackal may fairly be said to belong to the 
desert class. Most of the others are more characteristically inhabitants of 
grassy prairies; while some are partially sylvan. The Cottontail Rabbit 
(Lepus floridanus transitionalis) shown in Plate VII, at the head of this chap- 
ter, is a fair type of the fully counter-shaded, plain-colored terrestrial mam- 
mals.* These paintings of ours (rabbit, Ruffed Grouse, Copperhead Snake, 

*More strictly, however, this hare is a semi-patterned, semi-sylvan beast, and one in whose 
normal backgrounds there is a good deal of variation. 

127 



caterpillars, etc.) are, we believe, the first ever published which rightly illus- 
trate and in some respects do justice to the wonderful effects of obliterative 
coloration, based on the great law of obliterative shading. Many photographs 
of wild animals in nature (e. g., the ptarmigan shown in Fig. 41) illustrate 
the same thing with compelling force and beauty. Photography, indeed, is 
the great aUy of those who would expound the laws of obliterative coloration; 
and it is destined — more swiftly now that the underlying principles of that 
beautiful phenomenon have been disclosed and analyzed — ^to effect a funda- 
mental change in men's knowledge of the looks of animals in nature; and, by 
the same token, in the drawings and paintings men make of these wild ani- 
mals. The world has had enough, or must soon have had enough, of pic- 
tures of birds and beasts with their light-and-shade falsified to make them 
show. Outdoor nature as it really is, in the matter of the marvelous and 
exquisite visual correlations between animal and environment, offers to art, 
in this late age, an almost boundless virgin field. 

Figs. 84-89 and 93-94 are all photographs from live mammals, either in 
nature or captivity. Fig. 86 shows a tame hare upside down against a nor- 
mal background. (See also the photographed flat hides of mammals shown 
in Figs. II, 12, and 13 of Chapter II.) 

Mammals, totally unlike birds, butterflies, and even fishes and reptiles, 
are almost wholly devoid of really gaudy surface-colors. In some few cases, 
mammalian fur reaches or nearly reaches the standard of pure color in the 
direction of yellow, green, and possibly orange; but its normal and usual range 
of tint is through all the grades of neutral, from black to white, and through 
the entire scale of browns and grays, from vivid rust-color to cold bluish 
gray. When clear, gaudy color does occur on mammals, it is usually in the 
naked skin, as on the faces and rumps of certain monkeys and baboons. 
Now whether, as may well be the case, mammalian hairs are, as compared with 
the feathers of birds, the scales of butterflies, and the skin and scales of fishes, 
structurally incapable of producing brilliant colors, there is yet a sufficient 
ulterior reason why we should expect to find mammals brown and gray, 

128 



Fig. 84. Wild 
Cottontail Rabbit 
{Lepus flondanux 
transUionalis) in po- 
sltion. 'Obliter- 
ated' by counter- 
shading and faint 
ground- picturing 
pattern. 

Photographed from 
life, outdooi-B, Captive 
rabbit. 




Fig. 85. Domestio 
hare. Obliterative 
shading, etc. 

Photographed from life. 




Fig. 86. Domestic 
hare laid on its back, 
outdoors, 80 that the 
obliterative shading 
is reversed. 
Photographed from life. 




or at least much less brightly colored than birds, etc. The fact that they 
are so becomes in fact one more strong link in the chain of evidence in proof 
of the universal and paramount importance of concealing-coloration. Mam- 
mals (we will exclude the aberrant forms, as the bats — winged, nocturnal, 
and cavern-haunting — and the marine types) are characteristically flightless, 
and hence, in a great measure, tied to earth. In the forest, the outermost 
skyward excursions of the most arboreal species rarely or never take them 
into the gay regions inhabited by the more brilliant birds and butterflies. 
For these are masters of that unstable element, the air, and can go whither 
they please above as well as upon and through the ground and the forest. 
Hovering, flitting, perching lightly, always ready to resort to their wings in 
an instant if the perch should fail them, even many of the heavier members 
of this gifted class — even many of the birds, in short — are wont to pass most 
of their time in the brilliantly lighted outermost border of the forest, among 
the very tips of the slenderest twigs, where most of the fruits and flowers grow, 
but whither, even the most agile climbers of all the wingless mammals dare 
not venture. Metaphorically speaking, birds and butterflies are creatures of 
the grave and ponderous globe's exterior efilorescence, of the colored foam 
at the outermost edge of things, of the borderland between earth and sky; 
while mammals, man included, are citizens of the sober underworld. Plod- 
ding, earth-bound things, they walk upon the solid ground, and drive their 
tunnels in the darkness under it; while some of them ascend its skyward ex- 
crescences, the trees; but high as they may go they are still the creatiures of 
the 'underworld,' and the bright realm of butterflies and birds is still as a 
rule above them. By their life-laws, they are forever associated in close con- 
tiguity with things brown and gray and black;— mud^ sand, the dead leaves 
and twigs of the forest floor, rocks and pebbles, tree trunks and branches — 
and the black holes and shadows among all these things. Some few of the 
most arboreal kinds live in the realm of preponderant sylvan greenness (see 
p. io8 of Chapter XIX), and several of these (small monkeys, etc.) have olive- 
green or even clear green and sometimes yellow fur. But as no wingless 

129 



mammals attain, except in rare chance moments, to the bright and efflores- 
cent 'borderland,' the headquarters of the brilliant butterflies and birds, 
so are there practically no really gaudy mammals. Furthermore, it will be 
found, in almost every case, that the birds most closely akin, in ways of life 
and local habitat, to some dull-colored mammal, are themselves dull-colored; 
for birds are distributed ubiquitously, from their own special realm to the 
mammals' stronghold, the solid ground below. (See p. 107 of Chapter 
XIX.) Even outside the forest, the characteristic difference between the two 
classes, in habits and in accompanying coloration, is maintained. Wherever 
there is vegetation of any sort, down to lowly herbage, there it is the general 
wont of birds to feed and fly and climb on top of it, in the light, and amid 
bright colors, and the general wont of mammals, to feed and crawl about 
below it, amid shadows and dull colors. This generalization applies even to 
semi-aquatic birds and beasts. Wood Ducks swim high, and often sit on 
trees; kingfishers sit on stumps and branches above the water; Purple Gal- 
linules walk about, erect, on lily pads; and all these birds are marked with 
rich or brilliant water-colors. Otters, muskrats, beavers, capybaras, and 
other semi-aquatic mammals, swim either under water or almost submerged, 
showing only a low line of back and head. When they are out of the water 
they are always close to terra firma — on the muddy shores, in holes, or run- 
ning about under the bushes and weeds and tree-roots; and no one of these 
beasts is brightly colored. But here again we find that the bird tribe invades 
the mammal tribe's proper realm, and shares its system of dingy colors, 
though the mammal tribe cannot reciprocate. Thus there are rails and other 
marsh birds that live like skulking quadrupeds, on the ground below the reeds 
and bushes, and like them also they lack brilliant colors.* To sum up: on 
the bare fields and deserts, in the dusky forest shades, and below the taller 
vegetation in the marshes, there are 'mammal-colored' birds; but nowhere 
are there 'bird-colored' mammails. (A statement essentially correct, though 
for absolute accuracy it would need some qualifying.) 

* Except on their beaks, legs, etc., in the breeding season. 
130 



Equally in keeping with mammals' lack of gay colors and minutely elab- 
orate patterns is the fact that the great majority of them are nocturnal, hiding 
by day in hollow trees and holes in the ground. Nevertheless, in addition to 
a complete general adequacy, based, for the most part, on full and perfect 
counter shading, mammalian concealing-costume presents many beautiful 
types of generalized obliterative picture-pattern. Some of these are the sub- 
jects of our next two chapters. 



131 



CHAPTER XXI 

MAMMALS, CONTINUED. MARKINGS OF COUNTER- SHADED MAMMALS. THE 
MAIN TYPES OF THEIR OBLITERATIVE PICTURE PATTERNS 

WHILE the beasts of the open land, such as lions, kangaroos, and many 
hares, are notable for their almost complete lack of markings, al- 
though obliteratively shaded and tinted to a high degree, the costumes of many 
of the forest-haunting and tree-climbing mammals are characterized by strong 
and beautiful picture-patterns. Among these, there is perhaps none more 
potent and remarkable than the checkered sun-fleck and leaf-shadow pat- 
tern, worn by leopards, jaguars, ocelots, giraffes, and other sylvan mammals, 
and even by some snakes — e. g., several of the great constrictors. It varies, of 
course, from species to species; but its essential character is always the same, 
and it is always the handmaid of complete obliterative shading. Who has 
not noticed, in the forest, the flickering play of circular (or broken) sun-flecks 
and branched, encompassing leaf shadows? There is no more typical and 
familiar sylvan sight. Where the forest's crown is not too dense, this beau- 
tiful tremulous pattern marks all the brown ground where the matted dead 
leaves lie, and even checkers the sides and bases of some of the upright trunks, 
and the tops and sides of the naked lower branches. In deeper woods, where 
the leafage is extremely full and crowded, little or none of this sun-engendered 
pattern penetrates to the ground, which then is cloaked in uniform and quiet 
shade. But somewhere between the dim brown ground and the green and 
gaudy-flashing tree-tops there is always a large intermediate tract, where, 
amid trunks and spreading branches, twigs and scattered leaves, the check- 
ered pattern reigns supreme, dancing softly on the upper side of everything; 
and, helped by the varied glinting of the lower leaves themselves, it transmutes 

132 



-9 

•a « 



■-i 



2!f 



5? = 



S5 



5^ 



3 3 
3 c 




all that portion of the forest into a shimmering disorder of small, shattered 
lights and shadows, in which the actual solid details seem inextricably merged. 
To witness this effect in full, one must of course look at the scene from a 
point somewhat above it; but the pattern one sees in looking upward through 
the forest leaves, where they are not so crowded as quite to hide the sky, is 
of much the same nature. Indeed, this latter sort is in some respects more 
like that worn by leopards, etc., than is the true sun-fleck pattern. For the 
predominant effect of the leopard's pattern, and of that made by leaves against 
the sky, is of symmetrical dark marks on an irregular light ground — propor- 
tions which the sun-fleck pattern inverts, except where it is exceedingly pro- 
fuse. But what we see on the hides of these checkered sylvan beasts is really 
an apt and efficient generalization of this entire class of forest-patterns, includ- 
ing the much-used picturing 0} holes, done all in brown and black and golden 
forest-interior color. 

Among the species named at the beginning of this chapter, all but the 
giraffe are arboreal — that is, tree-climbing — ^while the giraffe's great height 
keeps him also in the region of frequent sun-flecks, as he feeds among low 
trees and lofty bushes. But the 'checkered' pattern in general is so charac- 
teristic of all lights and shadows in the woods, that, whether the beast so marked 
have for a background the variegated middles of trees, an under view of their 
leafy tops against the sky, or the flat brown forest floor, he will almost al- 
ways be adequately 'obliterated.' Everywhere, under leafy trees, exist these 
simple, elemental patterns, whose likeness on the hides of beasts men deem 
so beautiful. 

A leopard or a jaguar stretched out on a lofty branch, lying in wait for 
monkeys, his deceitfully counter-shaded and spotted coat dappled into still 
further indistinctness by the very shadows and sun-spots it counterfeits, 
must be about the most insidiously inconspicuous of hunters. (See Fig. 87.) 
But not all leopards and jaguars have this brilliantly obliterative forest-color- 
ation. Both species are rather prone to melanism, being sometimes almost 
wholly black, with scant traces either of counter shading or pattern. It would 

133 



be very interesting to discover whetfier or not the dusky individuals tend to 
be more strictly nocturnal in their habits; for they are certainly less well 
equipped for stalking and ambushing their prey in the broad daylight. 

The giraffe's or camelopard's pattern is simpler than the leopard's, con- 
sisting of but two well-marked color tones instead of three. The dark spots 
are rich brown instead of black, representing, as it were, a consolidation of 
the leopard's two darker tones. Giraffes, however, are subject to a good 
deal of individual (?), sexual, and geographical variation in the color and 
shade of the spots, as well as of the branching, irregular light bands by which 
the spots are divided. But their pattern always maintains its potency for 
obliteration, particularly in (low) woods, amid shimmering sunshine and 
leaf shadows, and more distant leaves and leaf-clusters and small branches 
silhouetting against the sky. In this, their foremost and special obliterative 
function, the mammalian and reptilian checker-patterns, cooperant with a 
full obliterative shading, must be reckoned among patterns which picture the 
background, like those much more elaborate and minute of many birds. 
(See Chapters IV, V, VI, VII, etc.) But they have also, in common .with 
almost all other patterns, and notably all that are sharp and bold, a simple, 
inherent obliterative effect. The sharp spots thickly scattered over the leop- 
ard's coat, and the eccentric patchwork-marks worn by his huge, stilt-legged, 
ruminant namesake, are in themselves a kind of mask or veil for the solid 
animal forms beneath them. Their bright, irregular and inorganic pattern 
takes from the visibility of their wearers' contours, and goes far toward effac- 
ing all the minor details and chance-shown lesser lights and shadows of the 
beasts' solid but obliteratively shaded forms. A glance at Figs, i, 14, and 
87 will tell the reader more about this than many words. In the case of such 
an animal as the Jaguar shown in Fig. 87, the perfection of the obliterative 
shading, denying as it does the presence of a solid body underneath the spots, 
tends to make these seem to belong to the background, even if that is not 
elsewhere spotted; and thus the simple 'retrocessive' obliteration is in part 
maintained. Nevertheless, a highly spotted (or otherwise closely marked) 

134 



animal, even though perfectly counter shaded, is of course out of place and 
more or less clearly visible against a perfectly plain background, because his 
figure silhouettes against the monochrome scene by virtue of its continuous 
pattern. This fact, or the converse of it, the noticeableness of a monochrome 
object against a patterned background, has already been demonstrated (Chap- 
ter III, Figs. 15-16). But few natural backgrounds, even in the open lands, 
are entirely immaculate; and hence some degree of flecking is nearly always 
advantageous, though often not essential, in an animal's obliterative colora- 
tion. 

There is a complete gradation of types between the leopards, ocelots, 
giraffes and boas, with their rich, specialized, forest-picturing 'checker' 
patterns, through such more weakly and ambiguously spotted beasts as the 
Ounce and Serval — the one apparently modified for snow and the other for the 
more open country — to the immaculate lions and (certain) antelopes. In 
the same way another beautiful and important type of obliterative pattern, 
namely, transverse striping, grades from its extreme development on the 
zebras and tigers, through various lessened and modified forms, to its last 
and slightest appearance on such animals as Livingstone's Eland, and other 
antelopes, from which it is but -a step to the stripeless ruminants and car- 
nivores of the open ground. Among all the bolder obliterative patterns worn 
by mammals, that of the zebras (Equus zebra and E. burchelli) probably bears 
away the palm for potency and beauty.* The wonderful photographs of 
live wild zebras (Figs. 88 and 89), here reproduced with the permission of 
their author, Herr Schillings, and his publishers, clearly illustrate one main 
phase of the obliterative force of these beasts' patterns. The briUiant cross- 
bands 'cut their wearers all to pieces,' and look exactly like the stripings of 
the lighted reeds across their, shadowed background. To aid in a fuller 

* Kipling, in one of his "Just So Stories," "How the Leopard Got His Spots," which we have 
just read for the first time, gives a most keen and appreciative description of the marvelous conceal- 
ing-power of the costumes of the zebra, leopard, and giraffe. He does not analyze the magic of these 
patterns, for he says nothing of the principle which underprops it, counter shading; but the magic in 
operation he has perceived and told about as no other man we know of has. 

135 



analysis of this effect, and kindred ones, we give also some diagrams — some 
imitation zebra pictures. Figs. 90, 91, and 92 are photographs of a zebra- 
shaped model cut out of fiat cardboard, and placed amid straws and imita- 
tion reeds or grasses, artificially arranged. In Fig. 90 the grasses relieve 
light against a dark background (as in the real zebra photographs by Schill- 
ings), and the zebra- to-be^now a wild ass (!) — is tinted uniformly with a shade 
intermediate between background and grasses. Being actually fiat, as the 
real live zebra is made to appear by its full obliterative shading, this mono- 
chrome model is not revealed by any look of solidity; yet it is visible and rec- 
ognizable, because its stripeless surface, with its organic and peculiar outline, 
interrupts and relieves against the striped pattern behind it. In Fig. 91, the 
same model, against the same background, has been converted into a zebra, 
by the application of the proper bands or stripes, — and notice the result ! The 
cardboard figure, standing almost where it stood before, and in exactly the 
same lighting, has practically disappeared from view. Its sharp bands carry 
the striate pattern of straws and dusky background across its every part, 
thereby obliterating it almost completely. (Schillings's zebras didn't hap- 
pen to have a fully and evenly striped background at the moment when he 
photographed them,* and therefore the effect of actual h&ckgTound-matching 
is only fragmentarily shown by his pictures.) Fig. 92 shows the same thing 
over again, with the difference that the striped background is made by imi- 
tation reeds relieving dark against white paper; the reverse of the former case. 
These two sorts of background are almost equally well suited to the zebra- 
pattern, as our pictures show. Both are imitated from nature, the one cor- 
responding to a landscape with brightly lighted grasses, reeds, or other tall 
and slender plants, relieving against dark ground or water, or against the 
shadowed interior mass of their own kind (see Schillings's pictures. Figs. 88 
and 89), and the other to a landscape in which such plants in somewhat open 
array relieve darkly against bright sky or water. Again, the shadows of these 
tall and linear plants — or even of plants more treelike and branching — cast 

* (not to speak of the extreme abnormality of the lighting). — A. H. T. 

136 




Artificial ass and zebra, looked at from the low view-point of an ambushed lion, showing the effacing-effect of the stripes in 
actual operation. (Study this picture from a distance.) 

Substituted for the SchillioE's photograph. Fig, 89t aince the book was printed. 



upon the sandy or otherwise pale-colored ground in sun- or moon-light, make 
a pattern very much like the zebra's.* So also with the reflections of such 
plants on quiet water. Scenes like these are doubtless typical of all the coun- 
try in which zebras live. For however arid and barren, through much of the 
year, are the hills and plains and plateaux over which the Mountain Zebra 
ranges, or used to range, they are yet clothed with tall plants of many sorts, 
including rank grasses, which no doubt stand erect for months after they are 
withered by drought. Furthermore, all beasts must have water, and so the 
zebras of the dry plains must needs make frequent visits to the nearest living 
sloughs and rivers. There, by the water's edge, tall reeds and grasses almost 
always flourish — often in broad beds of marshy verdure — and there, where 
all beasts meet to drink, is the great place of danger for the ruminants, and 
all on whom the lion preys. In the open land, they can often detect their 
enemy afar oflF, and depend on their fleetness for escape; but when they are 
down in the river bed, among the reeds, he may approach unseen and leap 
among them without any warning. It is probably at these drinking-places 
that the zebra's pattern is most beneficently potent. From far or near, the 
watching eye of the hunter f (bestial or human) is likely to see nothing, or 
nothing but reed-stripes, where it might otherwise detect the contour of a 
zebra. The extraordinary brilliancy of these stripes, which for the most part 
are clear black and white in sharpest contrast (much dimmed, of coiurse, by 
shadows, when the beast stands amidst vegetation), makes them effectively 
obliterative at a great distance, where weaker markings would merge and 
vanish, thereby allowing their wearer's contour to become apparent. Nor is 
this brilliance detrimental to the effect in a near view, — the stripes, as Schill- 

* One may satisfy oneself of this even in the snowy winter woods of northern Europe or America, 
where, in the slanting light of sun or moon, the shadows of naked trees lie thickly scattered on the 
pure-white groimd. Those of the trunks are mostly parallel, and perspective gathers them into nar- 
rowly banded patterns, while those of the branches, though much more irregular, also tend to form 
patterns of this type. 

t However largely lions and other rapacious mammals hunt by scent, it is not scent, but sight 
alone, that can serve them when they are dovm wind of their quarry; and sight alone must guide their 
ultimate killing dash and spring. — A. H. T. 



ings's pictures testify, still play their true obliterative part, 'cutting the beast 
to pieces' and wedding him to the strong and manifold striations of the veg- 
etation all about him. Indeed, a pattern so multiplexly and fundamentally 
'secant' 'cuts its wearer's aspect to pieces' in almost every view, only fail- 
ing to be purely obliterative when the beast is seen against a perfectly plain 
background. Against any appropriate background, on the other hand — as 
one of reeds and grasses, or even bare-limbed bushes and low trees, or sand 
streaked with the shadows of any of these plants, or quiet water striped with 
their reflections — its obliterative effect must be almost perfect. A slightly 
different phase of this pattern's use is that which comes into play when the 
zebra stands amid lower reeds (or other plants) with its upper parts relieving 
against the sky, or against dim, distant ground, or water. Its body then looks 
like the upward continuation of the grasses or reeds encompassing its legs; — 
the dark stripes continuing the reeds upward, and the light stripes between 
them continuing the sky or other pale background downward, so that the 
beast's contour, which otherwise could scarcely fail to show in this position, 
is stiU 'cut up' and concealed. This 'letting in,' or 'drawing down,' of 
sky into an animal's silhouette is a regular and frequent factor of obliterative 
coloration, occurring in many forms, in many classes of animals, but most 
notably among birds and mammals. The reader will hear more of it in the 
next chapter. 

Burchell's Zebra, the species photographed by Schillings,* is much like 
the now almost extinct Mountain Zebra in general coloration and pattern, 
but its light markings are more yellowish, and the secant bands are fewer and 
broader and somewhat differently distributed. On the whole, the Mountain 
Zebra has the more highly wrought obliterative costume, and that of Bur- 
chell's is one step down toward the much slighter pattern of the Quagga 
(Equus quagga). This beast, which has lately been exterminated, was banded 
only on the fore part of the body, and there irregularly, with light and dark 
brown. The transverse leg- and flank-bars of both zebras (but particularly 

* Strictly speaking, his beasts belong to subspecifically differentiated races of burchelli. 

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of the mountain kind), opposed to the more or less vertical body-bands, call 
for a word of comment. They are an example of 'secantly' obliterative mark- 
ing as distinguished from pure and simple picture-pattern. Striped up and 
down, the legs would continue the body's depiction of standing reeds or tufts 
of grass, but they might alsp look like an animal's legs, for their true form and 
general trend would be obscured but little. The legs, like the body, must be 
cut crosswise by secant stripes, if they are to be fitly disguised. As was ex- 
plained in Chapter XIII, such stripes achieve their full. effect only when 
aided by corresponding background-markings. Though the zebra walks 
amid upright grasses, etc., crisscrossing and horizontal stems and blades are 
of course common enough in his haunts to yield the required amount of co- 
operation to his essentially 'secant' horizontal leg-bands. When the zebra 
is lying down, with legs outstretched, these transverse leg-bands have of 
course a vertical direction, like the body-markings. This, perhaps, is the 
position which best favors, in the aggregate, the proper working of his ob- 
literative pattern. Still another detail of these wonderful harlequins' cos- 
tumes which demands especial notice is the delicately striped head-pattern. 
This is worn in almost equally high development by both zebras. It is by 
every test a picture-pattern. For, just as in the case of the picture-patterned 
birds (Chapter III, p. 32), this head-pattern of the zebra's is much smaller 
and finer than that of the body, as if to match a striped background decidedly 
reduced by distance — ^just such a one as the head, being the highest part, 
must normally have in relation to the lower body. Considering birds alone, a 
skeptic might suggest that the smallness of the head-pattern may be merely 
the simple physical consequence of the smallness of the hesid-jeathers; but 
such a theory would break down when confronted with the fact that there is 
a like proportion in the sizes of pattern between the heads and bodies of 
obliteratively colored hairy mammals. A single feather often contributes 
the whole of an important spot, or even several spots, to the general pattern, 
so that small feathers might mean small markings; but patterns made with 
hair are very different. It takes many hundred crowded hairs to make a 

139 



small detail of such a pattern as the zebra's, each separate hair contributing 
but a tiny share to the effect, so that the markings might be disposed quite 
arbitrarily on the beast's coat, as far as the mere form and character of their 
component parts is concerned. 

Near akin to the zebra-pattern is that worn by tigers. But the tiger's 
black stripes are narrower, further apart, and more broken and irregular, 
while its ground-color is tawny or deep golden brown instead of white or pale 
buff. The main obliterative principles, however, are alike in both. The 
tiger's coat is obliteratively shaded to minute perfection — darkest along the 
ridge of the back, lightest on the throat and belly, with intermediate shades 
for intermediate regions and smaller details of rotundity. His general color 
is that of the interiors of bushy thickets, reed-beds, the underwood of the 
loftier jungle, and all brown, half-shaded coverts; while his stripes picture 
vertical stems and slender trunks in shadow, and also the sun- or moon-en- 
gendered shadows that such plants cast upon the ground in opener places. 
As with the zebra, however, his pattern is essentially and intrinsically 'se- 
cant' and obliterative, and nothing short of a perfectly plain background 
can neutralize its power. He is a beast who hunts his prey by stalking, often 
in full daylight; accordingly, his huge form has been 'blotted out' by counter 
shading; he is likewise a beast who hunts in and among bushy and grassy 
thickets, full of upright 'stripes' of vegetation, and accordingly he bears a 
system of generalized dusky stripes upon his brown, obliteratively-shaded 
coat. The terrible inconspicuousness of the tiger in his native jungles has 
long been a famous fact, and no evidence on that score need here be cited. 
Suffice it to say that this inconspicuousness is due primarily to the beast's 
obliterative shading, and secondarily to his stripes and his tan-color, which 
have hitherto alone been held responsible, in the opinion of men. Turn a 
dead tiger or his stuffed skin upside down in a normal outdoor lighting, 
and, arrange him as you will against fitting backgrounds, he will be not dim 
and illusive, but conspicuous, because . of his now inverted obliterative 
shading. 

140 



The tiger has a vast geographical range, extending from the humid jungles 
of Sumatra to the snowy mountains and plateaux of northern China and 
Siberia; and like most widely distributed beasts and birds, it has developed 
several regional races, differing mainly in superficial characters. As the 
Ounce or Snow Leopard differs from the true leopard type in coloration, 
so, to some degree, does the North Asian mountain tiger differ from the jungle 
tigers of the South. Its ground-color is paler — sometimes almost ashen-white 
— and the stripes are scantier and more broken. These differences correspond 
to those of the beasts' habitats — the northern tiger living amid rocks and 
sometimes snow, in regions where tall upright stalks of vegetation are com- 
paratively uncharacteristic features of the landscape. Thus, in almost all 
cases, can one trace an apparent raison d'Stre of color- and pattern-differ- 
ences among nearly allied animals. There are a few cases more baffling, but 
the seeming obscurity of these doubtless depends on our ignorance of many 
fine points of difference or affinity in the beasts' life histories. Some animals, 
for instance, seem to have a superlatively elaborate obliterative equipment, 
while other closely allied species with nearly similar habits, living in the same 
regions, are patterned much more simply. This is the case with the two 
'harlequin' zebras and their relative the scantily half -striped Quagga. As 
the Quagga was banded only on its fore quarters, so the Thylacine, or Tas- 
manian Wolf, is banded only on its hind. Another Australian marsupial, 
the little ant-eating Myrmecohius fasciatus, is brilliantly zebra-banded from 
its shoulders to its tail. But among all the beasts that bear more fragmentary 
vertically-secant patterns, the African antelopes are probably the most note- 
worthy. Many antelopes of that continent, indeed, are almost or quite un- 
marked—smooth brown or gray, obliteratively shaded, with the regulation 
white or very pale-tinted bellies. But others are brightly, if some\diat scant- 
ily, striped, and sometimes spotted, on the back and sides and legs, with white 
and black — especially white. The most amply and regularly banded of these 
is the Koodoo {Strepsiceros kudu), which has many vertical white stripes on a 
dark-brown ground. This beast, as its markings would suggest, is an inhab- 

141 



itant of regions with rather ample vegetation — such as reedy river-margins. 
Indeed, its average environment and its disguising coloration are very much 
like the zebra's. In the same class of 'secantly' striped antelopian costumes 
is that of Livingstone's Eland, mentione4 a few pages back. This mag- 
nificent great antelope has black marks on its fore legs, while its brown back 
and sides, otherwise immaculate, are marked with five narrow vertical lines of 
gleaming white, extending from the ridge of the back about two thirds of the 
way to the middle line of the belly. These stripes, like those so much more 
numerous and bold worn by the zebras — and even the Koodoo — are secantly 
obliterative. They bring down, as it were, narrow slips of sky into the beast's 
smooth contour, when he stands upon an eminence and silhouettes against 
the distance — and thus they 'cut the contour up' and tend to obliterate it. 
Again, under other conditions, these stripes carry the aspect of stray gleaming 
grasses or reed-stems upward across the eland's earth-colored, obliteratively 
shaded body. In all such views, and in others where the 'picturing' effect 
is less pronounced, these stripes are definitely obliterative, always tending to 
' cut up ' the aspect of the eland's form. The Common Eland wholly lacks 
these markings, as do many other African antelopes; and here we have an- 
other case of notable costume-differences among animals with nearly or seem- 
ingly quite the same habits and environments. No doubt, however, there 
are really equivalent differences in the beasts' average surroundings, and in 
their behavior, even though these have not yet been noticed by man. Thus 
Livingstone's Eland may have a greater propensity to stand still in time of 
danger, or may spend more time amidst tall grasses and reeds, than those of 
its near relatives that lack the secant stripes. In the same way the more pro- 
fuse and variegated white markings of the Harnessed Antelopes, containing 
an admixture of white spots, are probably an indication that these beasts spend 
an unusually large proportion of their time in and about wet swamps and 
river borders, where flecks of water-shine — glints and stripes of sky-reflection 
— are common features of the scene. The small, irregularly circular white 
spots on the common Harnessed Antelope are indeed almost exactly like those 

142 



which are prominent in the patterns of certain semi-aquatic mammals; and 
they also correspond closely to the water-shine flecks of aquatic and swamp- 
haunting birds. (See Chapter XI, p. 6i.) Two beasts of this type are the 
African Water Chevrotain (Hyomoschus aquaticus) and the South American 
Lape or Paca (Coslogenys paca). Though belonging to diflEerent orders (the 
Chevrotain being a ruminant and the Lape a rodent) these two animals are 
much alike in general habits, while in pattern they are almost identical. 
The ground color of the Chevrotain's coat is richer and redder brown than 
that of the Paca's, but it bears almost exactly the same system of white flecks 
— irregular white spots, in places almost or quite confluent, and forming 
longitudinal chains or stripes. If these two beasts lived in the same swamps, 
naturalists would very likely consider their superficial likeness a case of ' mim- 
icry.' But since they live on different continents, there is no disputing the 
statement that they are independently equipped with water-shine patterns of 
the same simple, generalized type, which occurs the world over both on mam- 
mals and on birds. 

As the zebras' bands are vertically 'secant,' so lengthwise stripes, of which 
we see the first signs on the Harnessed Antelopes and the two water-beasts 
just described, are longitudinally secant, like those of certain gallinaceous 
birds and sparrows, etc. (Chapter XIII, p. 78). On mammals, this truly 
striped pattern appears in many forms and many degrees of elaboration, be- 
ing sometimes merely secant, with no very particular suggestipn of back- 
ground-picturing, and sometimes highly 'pictorial.' Many of the North 
American Ground Squirrels, and Spermophiles (Tamias and Spermophilus), 
are marked with bright, longitudinally striate patterns of black and brown 
alone. The Common Chipmunk {Tamias striatus), of eastern North Amer- 
ica, has few but highly developed markings, its one composite side-stripe 
being formed by a central whitish stripe inclosed within two black ones. 
(See Fig. 93.) Painted thus boldly on the little beast's obliteratively shaded, 
beautifully dim and flat-looking, honey-brown body, these markings much 
enhance its elusiveness by distracting the beholder's eye from any faint mod- 

143 



ulations of the creature's form which might otherwise be apparent; while each 
of these stripes looks in itself like a bright stick, twig, grass-blade, leaf-edge, 
or weed stem standing out above a shadow — either its own or a more general 
background-shadow, which shows on either side of it. Or again, this mark- 
ing suggests a shiny, cylindrical stick or steni, with its central streak of high- 
light, and the bordering shadows on itself, caused by its own curvature. Still 
another detail of ground-scene which these chipmunk-stripes suggest is the 
pattern made by sunlight falling between parallel twigs or stems — narrow, 
shadow-bordered sun-streaks on the earth or leaves or stones. They are, in 
short, generalized but most efficient picture-patterns. The western Four- 
striped Ground Squirrel (Tamias quadrivittatus) is colored and marked much 
like the eastern Chipmunk, but its stripes, besides being more in number, are 
narrower, and, as picture-patterns, perhaps even more generalized. Notable 
among the several other modifications of this pattern to be found on North 
American mammals is that worn by the beautiful Thirteen-lined Ground 
Squirrel (Spermophilus tridecimlineatus). The black intervals between its 
many light-colored secant stripes are traversed by lengthwise chains of bright 
spots, like slender flower-spikes or little leaves over shadow. On some sper- 
mophiles (as 5. grammurus douglassii), the secant pattern is reduced to a 
single broad black stripe along the middle of the back — an exaggeration of 
the dusky^' ridgepole' mentioned at the beginning of Chapter XX. 

An illustration of the obscurer type of generalized flecky background pat- 
tern on mammals was given in Plate VII. It is a type extremely prevalent 
among terrestrial mammals. Indeed, if we include all its oflEshoots, such as 
the system of regular, scale-like bright flecks on a dark ground, worn for in- 
stance by certain spermophiles, it is the commonest as it is the obscurest 
kind of mammalian pattern. It is worn by many terrestrial rodents, etc., 
of the open ground — e. g., hares, gophers, lemmings, spermophiles — and, 
variously modified, by many terrestrial forest mammals. Simplified to a 
close, bark-like grizzling, it is characteristic of many arboreal beasts, such as 
squirrels and some of the marmosets and lemurs. With very few exceptions, 

144 



patterns of this kind are accompanied by— or better, they are the accompani- 
ment of— complete and perfectly efficient obliterative shading. They grade, 
however, into the more bold and special types of pattern. Thus the ob- 
scurely flecky pattern of some lynxes shows here and there a spot which is 
halfway to the clean, sharp "rosettes" of leopards and jaguars. On the other 
hand, the flecky pattern grades downward into nothing, so to speak, and 
many mammals are almost or quite without markings, though perfectly coun- 
ter shaded, and colored brown or gray like the ground or tree trunks. Such 
are many rats, mice, shrews, etc., and, among large mammals, lions, pumas, 
wild asses, and many horned ruminants. 

An interesting parallel between the disguising-equipments of mammals 
and those of birds is furnished by the obliteratively marked young of many 
species in which the adults are without markings. The special obliterative 
costumes of young gulls and other birds was described in Chapter XIV. 
Among mammals, some of the deer and wild swine are notable examples. 
The adults are obliteratively shaded but unspotted, while the fawns and little 
wild pigs are super-equipped with an obliterative pattern of light spots, which 
lasts through their baby-time of comparative sluggishness and helplessness. 
These spots belong to the class of generalized flecky background-patterns, 
inclining on some fawns to sun-fleck and leaf-shadow picturing, and on pigs 
to water-shine picturing. Some deer — ^for instance the European Fallow and 
the Indian Axis Deer — retain the youthful pattern of obliterative flecks through 
life. This simple, spotty pattern is connected by various intermediates with 
other types of cervine and antelopine marking — such as the vertical bands 
of the Koodoo, the bands, stripes and spots of the Harnessed Antelopes, the 
softly 'ruptive' and background-picturing broad patches of whitish on light 
brown worn by the American Prongbuck {Antilocapra americana), etc. In- 
deed, with mammals as with birds, the special types of marking are all more 
or less smoothly connected one with another by intermediate types — worn, 
for the most part, by beasts which are evidently intermediate in habits also. 
But we have now mentioned and briefly analyzed the workings of the main 

145 



central types of mammalian picture-pattern cooperant with counter shading, 
as far as they are known to us. Wittingly and unwittingly, we have passed 
by a multitude of minor variations and adaptations, and may even have 
missed some types of foremost importance. 

The next chapter deals mainly with the patterns of mammals which lack 
diurnal obliterative shading. 



146 




I'll.. !i4. Mbega Monkey — a 'ruptively' and 'secantly' colored forest mammal. His light brush and long side-fringe < 
outward into his surroundings his sky-vist»-llke patch of light, which 'cuts his form to pieces.' 

Photographed from nature by C. G. Schillings. [Cf. Figs. 88-89.] 



PLATE VIH 





EXPLANATION OP PLATE VIII 



SUNRISE OR SUNSET. 

■ By Abbott H. Thayet. ■■•■, ,^ 

Presenting the very colors of the Spoonbills. 

'■ [See Plates IX and X.] 



ROSEATE SPOONBILLS. 
In morning or evening sunlight. 

. By Abbott H. Thayer. 
[See Plates IX and X.] 



CHAPTER XXII 

MAMMALS, CONCLUDED, ETC. PATTERNS OF MAMMALS THAT LACK DIURNAL 
OBLITERATIVE SHADING. SKY-MATCHING PATTERNS OF MAMMALS, AND 
A COMPARISON BETWEEN THEM AND THOSE OF BIRDS. FIXED 'DAZZLING' 
MARKS, AND OTHER SPECIAL PHASES OF PATTERN-USE 

IN strange contrast to the many beasts whose strongly, moderately, or 
faintly patterned ground-matching costumes are based on full and perfect 
obliterative shading, are the few whose bold, clear patterns seem to defy that 
foremost obliterative law.* Such are the skunks (Mephitis, Conepatus, and 
Spilogale) in America, the African Zoril or Cape Polecat {Zorilla striata), 
the Madagascan Galidictis striata and G. vittata, and that queer, badger- 
like stinker of the Javan riiountains, the Teledu (Mydaus meliceps). These, 
and many other small or medium-sized carnivorous mammals, are boldly 
pied with white and black — or dusky brown — and their white is all on the 
back and sides, while their under parts are uniformly dark.f We have here, 
as far as these patterns go, a complete inversion of the regular obliterative 
coloration. A true analysis of this case, which looks at first so mystifying, 
shows it to be in truth merely one more phase and token of the infallibly close 
correlation between animals' costumes and their environment and habits. 
Two diametrically different uses of white are equally consistent factors of 
animals' obliterative coloration. White on the underside, the usual culmina- 
tion of the almost universal obliterative counter shading, serves as a neutralizer 
of shadow, an adjuster and maintainer of the even balance between light and 
dark; white on the upper side, as worn in various forms and proportions by a 
good many aaimals, serves to imitate, to picture, the shining sky from which the 
underside is shaded. On the one hand, it is an all-important ingredient in an 

* See footnote, p. 123. 

t The "white" of these animals is in reality pale yellow, brown, or gray. — A. H. T. 

147 



oblitemtive compounding; on the other it is used, at its face value, for direct 
'background' picturing. Skunks, teledus, and the rest, long believed by natu- 
ralists to be colored for warning conspicuousness (proclaimant of their foul 
defensive equipment), have, in fact, the universal obliterative coloration. 
Seen from above on open ground, as men commonly see them, they are some- 
times very showy beasts, with their big, skylit patches of yellowish white, and 
their darkly shadowed undersides. But how different is the view their ter- 
restrial victims get of them! To these little animals — insects and small 
vertebrates of many kinds — they commonly loom up against the sky, towering 
high and huge as an elephant would above a skunk. Their big, bold patches 
of white and black are then about as potently obliterative as a beast's pattern 
can ever be — as is proved by our photographs (Figs. 95-97). According to the 
angle at which they are seen, their lustrous white* either nearly or exactly 
matches the brightness of the sky, while their dark patches are left to look like 
bushes, boulders, or more distant trees standing up above the horizon. All 
this is attested beyond question by our photographs, as the reader will agree. 
And he must consider that these pictures were taken in full daylight — a far 
severer test of such an effect than the dim light of night. For at night, sky and 
sky-pictures being correspondingly and greatly dimmed, the casual discrep- 
ancies of shade between them are reduced to almost nothing. The whole 
illusion, of course, is better in a dim light, since it depends wholly on bold, 
simple counterfeiting of background 'values' or shades. Skunks, and most or 
all of the other mammals that are colored like them, are grubbing terrestrial 
hunters, and nocturnal, and hence are served by their boldly pied white and 
black patterns in the manner shown by our pictures, but on the whole even 
more potently, by virtue of the dimness of the light in which they commonly 
hunt. The white stripe on the Common Skunk's forehead and snout — ^a mark- 
ing shared by several other grubbing ground-beasts, and among them some 
with light colored bellies, e. g., the badgers {Meles and Taxidea) — splays an im- 

* The actually pale yellow hairs are so lustrous as to look brighter, in such views, than lusterless 
pure white could. 

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Fig. 99. Conepatl or Prairie Skunk, seen I'roiii his prey's point ot 
view. [Cf. Fig. 95,] 

Stuffed skin, outdoors, photoe:raph. 




Fig. 100. Conepatl or Prairie Skunk, as in Fig. 99, but with sky back- 
ground out off. [Cf. Fig. 98.] 

Stuffed skin, outdoors, photograph. 



portant part in his disguisement. As he shambles over a field, with his seeking 
snout held close to the ground, this white stripe, in the view of the little ground 
beasts he approaches, 'lets down the sky' through his black head and fore- 
shortened bulky body, splitting the apparition into narrow, un-beast-like halves, 
which look like sticks or weeds or more distant bushes or boulders showing 
above the horizon. The several variations in the form and proportions of the 
sky-picturing white top-patterns of sk.unks and skunk-like beasts are all in 
more or less obvious conformity with differences in their wearers' ways and 
places of life. Thus the Common Skunk's main white pattern has a somewhat 
irregular, a waved and insected, lower outline; while that of the Conepatl or 
Prairie Skunk (Conepatus mapurito, etc.) is square-cut and straight; and 
these differences are doubtless, nay, obviously, matched by differences in 
the beasts' average backgrounds. For the eastern skunk is more often seen 
against a sky-line broken by trees, stones, and bushes, than is his desert- 
haunting relative. (Compare Figs. 99 and 100 with Figs. 95 and 98.) Al- 
though these photographs are from shapeless stuffed skins, they can be trusted 
in the matter of the main effects of the beasts' patterns, and even the main 
pattern-differences between the two species. Evidently, the Conepatl has 
just so much of his back sharply and levelly cut off by white, as, in the aver- 
age view of the little ground beasts he hunts, at the moments when it most 
profits him to be concealed from them, would show above the (unbroken) 
horizon. The pattern of the common eastern skunk renders the same serv- 
ice, but with the difference that it represents a sky-line notched by trees, 
etc., as we have seen. The Teledu of Java is marked much like the Cone- 
patl, though its white 'blanket' is narrower. Other beasts with more or less 
nearly the same habits, and the same general system of sky-picturing, are 
the Ratels (Mellivora capensis and M. indica), the Wolverine or Glutton 
{Gulo luscus) in some pelages, the Great Ant-eater (Myrmecophaga juhata), 
the Tamandua Ant-eater (Tamandua tetradactyla) , and, to some extent, the 
Tasmanian Devil {Sarcophilus ur sinus). But most of these beasts have 
even browner (or grayer) 'white' patterns. Many of them, on the other 

149 



hand, like several of those previously mentioned (skunks and badgers), have 
head- and face-masking as well as body-masking sky-picture patterns. Such 
markings, indeed, are very common among grubbing carnivorous and in- 
sectivorous mammals. Anyone who will seek through a big museum col- 
lection of mammals will be able to add many cases of both sorts to the above 
casual and fragmentary list. The profusely striped top-pattern of the 
Spilogale and the Zoril, etc., is merely another form of the same costume, 
and performs nearly the same service. It pictures sky seen through obstruct- 
ing twigs or narrow leaves, and is, with little doubt, significant of more sylvan 
or bush-land-haunting habits on the part of its wearers. It looks somewhat, 
also, like the converse of such a sky-scene — sharply contrasting linear lights 
and shadows on the ground, in moonshine. But the light markings, being 
almost white, are over-bright for this ground-picturing service, whereas they 
exactly fit the other. True, the effect of such brilliant, sky-lit stripes, con- 
trasted with the shadowed black of the under parts, is powerfully 'ruptive' 
in all views, even against the ground, 'breaking the beast up' into un-beast- 
like stripes and patches. Indeed, against the most brightly moonlit and 
most sharply shadow-brindled ground, such a beast must be pretty well ob- 
literated, and even his motion may be masked, — ^by the motion of the ground- 
shadows, cast by wind-swayed vegetation. But such conditions are highly 
occasional, and against open ground the spilogale's mantle of white stripes 
must often reveal him, especially when he moves about. It would seem that 
he might be much better equipped for concealment in almost all such views 
if he were counter shaded and more softly striped — or mottled, or even wholly 
unmarked. Think how ghostly-illusive against moonlit ground are the ob- 
literatively shaded and faintly patterned hares, and kindred beasts! Ap- 
parently, the dominant use of the spilogale's pattern is not ground-picturing, 
but the matching of sky glimpsed through dusky obstructions — a purpose 
which the obliteratively shaded, dimly patterned animal's costume could by 
no means serve. (See Fig. 103.) The spilogale probably has few large 
enemies to fear, and — ^just as with skunks, teledus, etc. — it is evidently of most 

150 



i'- *<^ 




Fig. 101. Spilogale, or Little Striped Skunk, seen from mouse's and cricket's position— his dark 
stripes passing for vegetation, and his white stripes for the sky. [Cf. Figs. 95-99, J 
Stuffibd skin, outdoors, photogi'aph. 




Fig. 102. Spilogale, or Little Striped Skunk, seen from men's and liawks' point of view. [Cf. Fig. lOt.] 

staffed skin, outdooi's, photograph. 





Fig. 103. A Compound Picture. (Photographic, except tor the upper renr-view of the Hare. The 
crouching Hare was photographed from life; the Skunk from a stuffed skin.) This picture, by show- 
ing the old familiar type of obliterative coloration alongside of the obliterative eflfect of white upper- 
surface patterns, so long supposed to make their wearer couspicuous, prepares the reader to discover 
that all patterns and colors whatsoever, of all animals that ever prey, or are preyed on, are, under 
certain normal circumstances, obliterative. Animals which need to escape notice when looked at 
from above, match the ground. Those that must not be detected when looked at from a lower level, 
match the sky, or whatever combination of sky, vegetation, etc., commonly forms their background 
from this view-point. Between these two extremes — if we count sky and sky-reflected-iu-water as one — 
are ranged the color-schemes of most of the animal kingdom. 

In this illustration the Skunk against the sky loses the white parts of his silhouette, and his dark is 
left to look like bushes, etc., in the background (A). On the other hand, the Skunk against the ground 
loses his dark parts, and his white, though often, as here, conspicuous in itself, has a largely inorganic and deceptive contour, and. when seen 
amid obstructing twigs and leaves, especially at night, is potently obliterative (Cf. Figs. 104-106). It is in fact not pure white, but 
nearer to the color of bleached dead leaves and twigs. The Leaping Hare's white rump vanishes against the sky (0), from the sight 
of the creeping fox, or other quadruped pursuer. The fox's eyes are, at that moment, lower than the Hare's tail, and he sees it 
against the sky, (or, in the woods, the sky's light through the leaves). (D) shows a man's view of the same hare, and explains why men 
have thought this white conspicuous. To a young hare this white rear or the mother would present the same difficulty as to the fox. On 
the other hand, a crouching Hare, so admirably merged into his surroundings when looked at from above, C^), is boldly conspicuous 
when seen from the position of a mouse or cricket, as in {F), and in the detached figure of a Tame Hare, (GO- If a mouse could tneorize, 
he would know the mcunk to be obliteratively colored, but would consider the hare, except when it was running away from him, a most 
conspicuous animal, thus reversing men's notions. In this illustration, the hare in profile against the sky would be still more convincing 
were his members extended for action, showing a more revealing outline. [Cf. the Domestic Hare (GO.] 



importance to him to be masked for the eyes of the little ground beasts on whom 
he feeds. (See Figs. 101-102.) 

Seen against snowy ground, which is common enough through a large part 
of the eastern skunk's range, a boldly pied pattern of white and black, such 
as he wears, is of course most potently 'ruptive.' But it does not truly oblit- 
erate, because all the black part of the beast is left rankly conspicuous, and has 
too peculiar a form, in such a view, to be easily ignored, or mistaken for a land- 
scape-detail. Northern skunks, however, vary a good deal in pattern, and 
the very whitest of them are doubtless well disguised, in certain views, against 
snowy ground, particularly amid trees and sticks and stones and bushes 
and other inanimate dusky details. In this case, as throughout the whole 
great field of phenomena we are studying, it stands to reason that a special 
development of costume must serve minor as well as major ends.* But how- 
ever potently 'ruptive' (and therefore essentially obliterative) in their effect 
when seen against the ground the whitish patterns of skunks and skunk- 
like beasts may sometimes be, the paramount function of these patterns is 
certainly the picturing of sky, as our figures show (Figs. 95-103). Both 
uses are served, perhaps almost in equal measure, but with the balance of 
importance probably tipped somewhat toward the groundr-vc\2itchm.g function, 
by the wholly or almost wholly white costumes of several snow-land animals. 
Such — to begin with those least remote from the skunks — is the rare, bear- 
like Ailuropus melanoleucus, of Thibet; such are the Arctic hares and foxes, 
the boreal weasels and some of the boreal hares, and the Polar Bear. Almost 
all of these, and their counterparts among boreal and Arctic birds — the ptar- 
migans, the snow buntings, the Snowy Owl, and the White Gerfalcon — almost 
all of them, mammals and birds alike, have a few sharp black markings in their 
mainly immaculate white costumes. These evidently serve as what may be 
called 'distractive' or 'fixed dazzling' marks. They are, in most cases, too 
small to show except in a very near view— when, by their sharp but isolated 

* Or, in terms of the Natural Selection theoiy, that each development is the prodiict of the sum 
oj all its uses, big and small. 



and noncommital conspicuousness, they tend to draw and hold the eye's 
attention, — in a sense, to dazzle it, so that it less readily discerns the faintly 
shown snow-white body of their wearer. The working of this principle is 
illustrated by Figs. 104-106, Most ptarmigans have black tails, which, folded 
and largely hidden by white 'coverts' when the bird is skulking, show as nar- 
row, sharp black marks, drawing the eye to a point away from the bird's 
rotund body, 'dazzling' it slightly, and presenting it with a view of what 
might be a little twig or stone or other dusky landscape-detail. Some ptar- 
migans in white winter plumage have also a black face-mark, which serves 
the same purpose, and also masks the bird's round and lustrous eye, in the 
manner explained in Chapter XIV. The Snowy Owl and the White Ger- 
falcon are more profusely flecked with 'distractive' black marks. Notwith- 
standing the special inherent 'dazzling' function of such markings, they all 
belong essentially to the 'picture '-pattern class. For, if they did not also 
look like dark landscape-details, they would in the long run tend to reveal 
rather than conceal their wearers. The northern weasels in their white winter 
dress have 'distractively' jet-black- tipped tails. Polar Bears and Arctic 
Foxes have no such markings, unless we count their black snouts and dark 
eyes. Very likely such beasts when they are skulking partly close their eyes, 
masking their too characteristic circular or oval form. The little Thibetan 
Snow Bear (Ailuropus), on the other hand, has more than a mere 'distrac- 
tive' display of black in its white costume. Its legs, its ears, and a narrow 
shoulder-mantle are solidly black, and it has black spots around its eyes. 
Thus it is well fitted for obliteration, or great inconspicuousness against 
either snowy ground or sky, in a country full of dark boulders or bushes, 
or both.* In much the same manner, and presumably for life amidst back- 
grounds of the same general aspect, is the Kamchatkan white-shouldered Sea 
Eagle disguised. But in his costume the dark preponderates over the white. 
One more principal phase and function of mammalian sky-matching 
costume remains to be described. That is the 'obliteration' of fleeing deer, 
* The white breast-marks of several of the black bears belong in this same class of obliterative patterns. 

152 




Fro. 104. 



o o 



o 



Fig. 105. 



Figs. 104-105. These dii^rams illustrate the obliteratiTe effect on faintly-showing contours of sharp and strong internal marks. The 
reader will see, if he recedes from the picture, that the Butterflies' or Letters' contours near the bold marks vanish^ while those apart firom 
markings remain perfectly distinct. The markings, at the same time, ally themselves to kindred details in the background. 




Fig. 106. 



FiQ. 106. Here the spectator will discover, if he recedes far enough, (seven or eight yards in a bright light) that all three of the 
monochrome butterflies, even the dimmest, can be seen further, or in a less illumination, than the normally and brightly patterned 
one. This latter /a<fe< prst. This shows how contrasted juxtaposed color-notes efface each other, so that contrary to the old theories 
they are not so good as monochrome for revealing the wearer, even in the open, while, seen through the average tracery of out door 
vegetation^ they almost ^wxranttt disguise and concealment. See Plate V. 



antelopes, hares, etc., by white tails and rumps. More characteristic even 
than the grubbing carnivores' sky-matching ^eoc^patterns are these more or 
less 'eclipsable' rear-end flight-masks of timid, fleet ruminants and larger 
rodents. When these beasts flee at night before terrestrial enemies — which are 
nearly always of lower stature than their quarries, and in most cases addition- 
ally fated to look upward at them by the fact of the quarry's high- jumping 
gait, and their own crouchitig and slinking — when these hunted beasts flee 
thus, their brightly displayed sky-lit white sterns blot out their foreshortened 
bodies against the sky. In the night, the illusion must often be complete, 
and most beneficent to the hunted beast, who by its aid may often just avoid 
the lion's or the tiger's or the cougar's or the cheetah's killing second spring;— 
vanishing into air, as it were, before the predator can get his aim for the leap, 
or before he can perceive the direction of his quarry's flight. For photographic 
illustrations of this marking's obliterative effect, see Figs. 107-115. Such 
rear-end sky-pictures are worn by most fleet ruminants of the open land, and 
by many rodents with more or less nearly corresponding habits — notably 
the hares, and several smaller running or leaping rodents whose terrestrial 
enemies are many of them beasts of low stature — ^like weasels, minks, snakes, 
etc., and foxes, that slink and crouch. The ruminants that lack such mark- 
ings are most of them either extremely big and powerful — like some of the 
huge African antelopes, and almost all the bovine beasts — or else they live in 
dense tropical forests, where at night there is very little 'overhead' light for 
them to relieve against. Some of the little South American jungle deer are 
good examples of this forest-haunting class. 

All these various sorts of wonderfully effective sky-picture patterns are 
worn by animals that are habitually or most commonly looked up at, either 
by their enemies or by their quarries. Indeed, the presence or absence, the 
high or scanty development, of such markings in an animal's pattern, seems to 
be a direct and accurate indication of whether, in the average view of the 
creatures from whom it most profits the animal to be concealed, it comes above 
or below the horizon line — and of the largeness of the preponderance in either 

153 



direction. Thus gulls, terns, and many other sea birds, which fly between 
blank ocean and blank sky, getting their food from the water, are largely 
cloaked in sky-matching white. So, among land birds, are the often-men- 
tioned Snowy Owl and White Gerfalcon, which fly and hunt over treeless 
barrens and the bare ocean-shore. So are most swans, some geese, some pel- 
icans, and several herons, storks, ibises, cranes, etc., — birds that swim or 
wade, seeking their food below them in the water, and doubtless subject, in 
all or most cases, to persecutions from aquatic enemies. Showy as these 
birds are against the muddy ground and dark-green vegetation, they are 
equipped for the utmost possible inconspicuousness when seen from below, 
against the sky. Viewed at the proper angle, they must, like the skunk's 
back, be almost invisible, especially a,t night. (An opaque body directly in- 
terposed between the beholder and the zenith cannot fail to show dark, however 
colored; but the upper surfaces of a snow-white opaque body looked at in an 
obliquely upward direction, so that it is seen sky-lit and at the same time 
against the sky, may exactly match the brightness of its luminous background 
— all of which is shown by Figs. 107-115.) Plates VIII, IX, and X, 
with their Flamingoes and Roseate Spoonbills, reveal the simple fact, which 
seems never to have been noticed, that these traditionally "showy" birds 
axe, at their most critical moments, perfectly 'obliterated' by their colora- 
tion. Conspicuous, in most cases, when looked at from above, as man is apt 
to see them, they are wonderfully fitted for 'vanishment' against the flushed, 
rich-colored skies of early morning and evening; and such are their normal 
backgrounds, at their chief feeding-times, in relation to their aquatic enemies 
(sharks, alligators, tortoises, anacondas, etc.) and those of their prey that 
see at all. Of course, against the dawn or the sunset itself, these birds must 
show dark, just as with white against the zenith; but the rosy hues very com- 
monly suffuse both sides of the sky, so that, in either twilight, the Spoonbill's, 
Ibis's or Flamingo's illuminated ruddy color very often has a true 'back- 
ground' of illuminated ruddy sky. Further, the side of such a bird actually 
sunlit, at early morning or late afternoon, is made to glow so brilliantly as to 

154 





Fig. 107. Prong-Buck as commonly 
seen by all animals whose eyes are on a 
lower level than its rump. (This, of course, 
includes the Prong-Buck's terrestrial ene- 
mies, such as wolves and cougars— not to 
speak of the beast'sown young, which have 
been supposed to use their parent's snow- 
white stern as a "banner*' to follow iu 
flight.) 

In all these photographs from a stuffed 
beast, the rest of the animal is much more 
conspicuous against the ground than it 
would be in nature. 

Photoeraphed trom a stuffed skin. 
Soiled rump-mark covered with white rabbit skin 



Fig. 108. Prong-Buck's obliterative 
rumj)-mark seen against the ground, as 
men see it, their eyes being on a higher 
level. 

Photographed from a stuffed skin. 
Soiled rump-mark covered with white rabbit skin. 



Fig. 109. The same as Fig. 107. but with the 
Prong-Buck's legs and the landscape shaded 
more nearly into one flat 'tone,' such as the 
beholder would really see in the night. Body 
and legs, not coming against sky, would, at 
night, be invisible, or very nearly bo. 

Nature, in such cases as the Hare's and Prong- 
Buck's, evidently 'obliterates' with white exactly 
as much of the animal as his carnivorous enemies, 
when close upon him, would see against the sky, 
to guide their flnal leap. 

Retouched photograph of stuffed skin. 



Fig, 110. Prong-Buck against the sky, presenting a con- 
spicuous silhouette of all but the rump-mark, which would 
show were it of any darker tone than wMfe. 

Soiled rump -mark covered with white rabbit skin. 

Photograph of stuffed skin. 

{Except where the contraiy is expressly stated, all our photographs are 

absolutely unretouched.) 





Fig. 111. The common aspect of animals showing against night sky, if they have no ivhiu- iop-paUerng. 





Fig. 112. (Dead) Northern Hares seen from 
the level of a creeping fox. 

These photographs show that from this view- 
point the so-called banner-mark, the white, is 
precisely what does not show. 



Wa. 113. Dead Northern Hare, seen from men's level. 
Hares in danger from over-head foes, e. g., birds of pr&y, 
doubtless resort to crouching 'invisible' rather than to run- 
ning, while, on the other hand, enemies which trail them 
/(W'ce them to leap away. 

Photographed, ont-dnoi's. 




Fig. 114. White card, as in Fig. 115, but invisible against the sky, because the camera was lower than 
the card, just as a panther or fawn would be lower than the deer's buttocks. 

Photo^aph. 




Fig. 115. A white card— as it were a detached rump-mask against the 'ground.' 
Photograph. 



look like a real sunset or dawn, repeated, on the opposite side of the heavens, 
either east or west as the case may be. 

All these white and pink (or red) fishing-birds and vegetable-eaters have 
the habit of staying more or less quiet, for longer or shorter periods, in the 
near vicinity of their aquatic prey and enemies. Egrets and white herons 
stand hour-long motionless or wade cautiously about in shallow ponds, rivers, 
lagoons and estuaries, — ^ready with poised head and lancelike bill to stab the 
first fish or frog that comes within their reach. (See Figs. 116-118.) White 
pelicans fish while swimming; but the brown pelicans plunge headlong from 
on wing into the water, catching their prey by violent abrupt assault, like 
the gannets, the terns, the kingfishers, and the Osprey; and all these plunging 
fishers have characteristics of coloration in common, which are not typical 
of the stealthy fishers. These consist in brilliant ruptive patterns, chiefly on 
the head, but sometimes also on the wings and body — ^patterns which doubtless 
have the effect of confusing the suddenly assaulted quarry as to the exact 
position and the true form of its attacker. Such are the tern's black head- 
caps, the black or dark marks about the base of the Common Gannet's pale 
sea-green bill, the clearly-contrasted brown and white stripes and patches 
of the brown pelicans' heads, the motley costumes of kingfishers, etc. At 
the instant of attack, such markings 'break up' and confuse the apparition 
of the attacker, doubtless often to the bane of the attacked, whose life or death 
must often depend on the turn of a hair toward quicker or slower, surer or less 
sure darting off. Stealthy fishers, on the other hand, would in many cases be 
misfavored by such 'ruptive' markings, which during their quiet stalking and 
watching would increase their conspicuousness against the sky. On the 
other hand, even the black wing-tips and like markings of gannets and other 
plunging fishers, serve as 'dazzling' and ' distractive ' marks, — like those 
of. the tails of winter ptarmigans and weasels — at the moment of the bird's 
arrowy arrival with part-folded wings (and tail) among his finny prey. 

Then there are two or more classes of animals merely patched with sky- 
pictures. Such are the more or less largely white-backed skunks, and kin- 



dred mammals, and the many arboreal birds and several arboreal mammals 
which have biggish white spots or patches on their backs and sides. The 
ground beasts of this group are, as has been explained, specially equipped 
for concealment against the horizon-bordering sky; while the tree birds' and 
tree beasts' more or less ample, irregular patches of sky-picturing white are 
in evidently just proportion to the greater or less amplitude and frequency, in 
their average backgrounds, of sky vistas, and light foliage vistas amidst dark 
leaves and twigs and tree trunks. 

Next and last in order come the terrestrial and semi-terrestrial birds and 
other animals which are equipped for concealment against the landscape below 
the horizon, and have little or no hint of sky-picturing in their costumes. Such 
are many woodland ground birds, notably the brown tropical ones described 
in Chapter XIX. Such also are most of the terrestrial woodland mammals; 
such, again, are snipe, goatsuckers, and many of the small, close-lying Gal- 
lince (most arboreal species have fragmentary sky-pictures — see the Cock 
Ruffed Grouse in Plate II) ; such are most frogs and toads and many ground 
lizards; such are sand crabs; and such, in the most marked degree, are many 
terrestrial snakes — ^for instance the Copperhead, shown in PlateXI (Chap- 
ter XXIII). Most of these creatures are patterned with elaborate ground- 
pictures, and on some species, like the Copperhead snake, these have reached 
a very high degree of specialization. Because of their low stature and their 
ground-haunting, close-lying habits, such animals as these scarcely ever, in 
the view of predators or quarries, stick up above the horizon line. They are 
colored, with exquisite efficiency, for obliteration or extreme inconspicuousness 
when looked down at, against a background of mother earth and her lowly 
vegetable mantle. If men were Lilliputians, and looked up at the flanks and 
back of the Copperhead snake, as in reality they look down at the sky-pic- 
turing back-pattern of the piebald skunk, the snake's coloration would seem to 
them just as "conspicuous" and inappropriate for disguise as the skunk's has 
always seemed. "It's all in the point of view;" — and if we would learn the 
true, the compellingly apparent significance of animals' costumes, we must 

156 



KXPLANATION OF PLATE IX 



ROSEATE SPOONBILL. 

Before sunrise or after sunset; matching the sky behind it, 
(i. e., the western sky at dawn, or the eastern sky at sunset). 

SUNRISE OE SUNSET. 
A -typical sky, much like the aspect of the Flamingoes. 

" ^y] RED FLAMINGOES. „^M/i'''] -^^f'i.':'' 

Before sunrise or after sunset, matching the sky 
behind them, as in the Spoonbill picture. "% . 

By Abbott H. Thayer V 



These various sketches of Flamingoes and Spoonbills show how wonderfully such birds match 
or reproduce the colors of morning or evening skies to the eyes of the inhabitants of the water in 
which thg^3|; wade— both their enemies, such as anacondas, alligators, sharks, etc., and such of 
their prey aa can see them. 

Conmitinly, the bird's upper outline 'melts' into the sky, leaving the rest of his contour, seen 
through the water, agitated and muddied by his feet, to be lost in the indeterminate color-mass of 
the flock. Shaken and jumbled by the contmual agitations of the water, the image of the flock 
retains, for eyes beneath the surface, only its color and its positioQ,, both of which coincide with 
those of the dawn or sunset, (though on the other side of the heavens) or the flushed sky opposite. 

Through aU stages of twilight this living mass, seen against the less lighted parts of the sky, 
blends into it, undergoing kindred changes of illumination, and when full Bunlight bathes it, its 
lighted side blazes out into a perfect representation of the dawn or sunset itself, though in the 
opposite quarter. In the case of the Red Flamingo the bird's legs, including its feathered thighs, 
are purplish instead of orange-red, in keeping with thfe color-gradation of the sky, which is, at 
these hours, commonly purplest at the lowest point, having its purest reds and oranges a little 
higher up. Thus, each part of the bird has every possible opportwiity of matching its 
backgirotuld.— A. H. T. 



PLATE IX 




AHaBM acOO.BAITIMORE. 



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PLATE X 





Fig. 116. Imitation Egret without plunics- 
nhotocraphed against white (subetitutM tor 
skv). to show that the shadows which 
reveal the form come at the very pomtg 
normally covered, at the breeding-s^fton, 
by the so-called ^'nuptial" plumes, Th^ 
points are indicated by the arrows. The- 
knife-like thinness of the throat, where 
plumes would incommode him, largely 
obviates the need of them at this pointy 
by minimizing the shadow. 




Fig. 117. Imitation Kgretiu nuptial dit".s, 
photographed against black, to show the- 
position of the pTunies. 




Fig. 118 a, A is a section of the Egret. B" 
the root-like plumes, f the dark under side- 
which they hide. The part of a heron's 
neck that uormally bends backward as he- 
stands has the roofs rUlge-pole in fronf, and 
the enves behind. 




Fig. 118. Imitation Egret in nuptial jjIu- 
mage, photographed against white, showing 
the effect of the plumes in effacing the shad- 
ows, thus rendering the bird almost invisible- 
when seen against the sky. This is achieved 
on the model, as on a real Egret, in the only 
conceivable way : the plumes extend down- 
ward and outward like a roof between the- 
beholder's eye and the shadow to be covered. 
Because of this roof-like position, they stay 
illuminated throughout their whole length, 
and interpose their bright fringe between 
the beholder and the shadowed uiidersides 
of the neck and body. The fact that these 
fringes cj-oss the bird's contour, and /oWoiu 
that of the vegetation in which he stands, 
greatly helps the concealment. White fluffs 
or fringes of this genei-al character, screening. 
the too deeply shadowed ahdomival space, 
between the legs, are very common among^ 
birds and mammals. 



first learn to look at them not solely from the point of view of man, who neither 
flies nor climbs nor crawls, but also from that of the other animals, big and 
little, winged and creeping, with whom the bearer of the costume in question 
has in any way to deal. And by no other phenomenon of obliterative colora- 
tion is this fact so forcibly brought home to one's mind as by the perfectly 
consistent and unbrokenly intergraded chain of sky-picturing and ground-pic- 
turing patterns and costumes of birds and mammals. 

One more notable phase of sky-picturing's occurrence on birds must here 
be cited, namely, its part in the costumes of some ground birds of the open 
land. The American Bobolink (Dolichonyx oryzivorus) for instance, in the 
summer plumage of the male, is marked and colored much like a skunk — as 
its colloquial name "Skunk Blackbird" attests. Roosting at night in weeds 
and grasses some inches above the ground — as it almost certainly does — it is 
disguised, for the eyes of prowling predators, almost exactly as the skunk, 
himself a prowling hunter, is disguised for the eyes of smaller ground animals. 
The Black Lark Bunting {Calamospiza melanocorys) of middle western North 
America, likewise a bird of the open ground, has a big, sky-matching white 
patch on its wings; and several Longspurs (Calcarius, etc.) and Larks (Alau- 
didce) have markings of the same nature, and kindred habits. 

Sky-picturing marks are sometimes found in evident cooperation with 
wholly different disguising effects. Thus the common American Raccoon 
(Procyon lotor) has a rim of white or very pale brown bordering its largely 
dusky face ; and though in many views this must serve as an obliterative sky- 
matching mark, like the many kindred markings of grubbing carnivorous and 
half-carnivorous mammals, yet it also admirably serves to make the Raccoon's 
whole face and head, in front view, look like the end of a hollow log or stump, 
with a shadowy, dark interior and light, encircling outward rim. (See Fig. 120, 
No. 36.) This trick of coloration, which has already been mentioned in con- 
nection with the sloths (Chapter XX), is of widespread and frequent application 
in the animal kingdom, as a glance at Fig. 120 will convince the reader. Here 
we have many kinds of 'holes' with encircling light rims or margins; some 

157 



of them real and some imitated — ^pictured — ^by the surface-patterns of animals. 
Some of these counterfeits are very highly developed and effective (e. g., the 
whip-poor-will, No. 50), while others are comparatively obscure. But even so 
casual a rendering of this effect as is achieved by the young owl's face (No. 
i) may well benefit the animal that wears it, in the long run — since it tends 
to mask the creature's true structural form and look of life. 

A good many mammals* have the form of 'distractive' coloration men- 
tioned in the case of pheasants, etc. (Chapter XVII), namely, strongly banded 
tails and delicately marked (or unmarked) obliteratively shaded bodies. 
Almost all are beasts that live in holes, and dart into them in time of danger; 
and their banded tails undoubtedly work for their safety by diverting the pur- 
suer's attention and attack to a point behind them, in the essential moment of 
their darting forward into their retreat. Even if they are actually seized by the 
tail, they may still tear free and escape — whereas a body-grip would far oftener 
succeed. When such beasts a^e quiet, their tail-bands act obliteratively, to 
the full — as we have already seen in the case of birds (Chapter XVII). 

We have now examined what seem to be the main principles and many of 
the chief phases of disguising coloration among mammals. But, as I said 
before, it is likely, nay, certain, that many types of particular interest have 
escaped the notice of my father and me. It is true also that we should be ad- 
venturing beyond the proper scope of this book if we tried to give more than a 
clear sketch, illuminated by a few chosen representative details, of any one 
branch of the big and intricate general theme. Our next subjects — ^fishes, 
reptiles, and batrachians — must be considered even more briefly, owing to 
our very fragmentary knowledge of these animals. 

* Spermophiles, lemurs, raccoons, etc., etc. 



158 




Flii. ll'.l— (1.) 





Flc;. n'.l-(L'.) 




k;. ir.l-(:i.) 





Fig. 119. Diagram to illustrate the crtectol the animals' 
markings shown in Fig. 120. These lour figures show a 
graduated development from No. 1, which represents nothing 
substantial, to No. 4, which represents an edge of substance 
showing against a shadowed cavity beneath. Animals' 
markings, almost invariably, are on the geuernl principle ot 
No. 4. 



Fig. 120. Bits of animals' patterns, all repre>cutiiig holes^ 
i. e.j shadowed cavities over which sharply defined edges 
"relieve" (like wood, leaves, rocks, etc). Among these are 
mingled reproductions of actual holes to show b<nv close- 
is the resemblance. (See Fig. 119.) 



Fig, 119— (4) 



INDEX TO FIG. 120 

1. Young Bam Owl's face. Photo. 

a. Bit of Boa's pattern. Photo. 

3. Baby Woodcocks' (.Philohela minor) hacks a,nd heads. Photo. 

4. Hollow among stones. Photo. 

5. Hollow among stones. Photo. 

6. Part of adult Woodcock's head. Photo. 

7. Bit of Whip-poor-will's back. Photo. 

8. Bit of Rattlesnake's pattern. Photo. 

9. Slivers of wood over shadow. Photo. 

10. Hollow among stones. Photo. 

11. Curled leaf. Photo. 

12. Bit of Ocelot's pattern. Drawing from photo. 

13. Bit of Python's pattern. Drawing from photo. 

14. Bit of Ocelot's pattern. Photo, from halftone. 
IS- Split bark over hollow in a tree. Photo. 

16. Bit of Whip-poor-will's back. Photo. 

17. Adult Woodcock's eye. Photo. 

18. Top of baby Woodcock's head. Photo. 

19. Fore part of a sphinx caterpillar. Photo, from drawing. 

20. Open mouths of young birds. Photo. 

21. Bit of Rattlesnake's pattern. Photo. 

22. Bit of Copperhead Snake's pattern. Photo. 

23. Shadowed holes in a crumpled hide. Photo. 

24. Markings on a kind of frog. Drawn from photo. 

25. Fold in a hide. Photo. 

26. Slivers of wood over shadow. Photo. 

27. Bit of Woodcock's pattern. Photo. 

28. Bit of Copperhead Snake's pattern. Photo. 

29. Baby Woodcock's head, etc. Photo. 

30. Shadow between mushrooms. Photo, 

31. Bit of Boa's pattern. Photo. 

32. Cracks among rocks, and Ptarmigan chick, 

33. Bit of Rattlesnake's pattern. Photo. 

34. Holes (insect borings) in a board. Photo, from half tone. 

35. Head of sphinx caterpillar. Photo, from drawing. 

36. Raccoon's face. Photo. 

37. Bit of Ocelot's pattern. Drawn from a photo. 

38. Bit of the Serval's pattern. Drawn from a photo. 

39. Baby Woodcocks' heads, etc. Photo. 

40. Big knot-hole cavity in a tree. Photo. 

41. Big knot-hole cavity in a tree. Photo. 

42. Holes in a (tanned) hide. Photo. 

43. Holes in a (tanned) hide. Photo. 

44. Meadowlark's breast-mark. Photo. 

45. Hole in an old boot (moccasin). Photo. 

46. Part of a feather from a female Golden Pheasant's tail. Photo. 

47. Tom dead leaves. Photo. 

48. Tom dead leaves. Photo. 

49. Tom dead leaves. Photo. 

50. Head (crown) pattem of the Whip-poor-will. Photo. 



159 



CHAPTER XXIII 

riSHES. THE MOST UNIFORMLY AND NEARLY INVARLABLY COUNTER SHADED 
OF ANIMALS. THEIR COLORS AND PATTERNS. OTHER MARINE ANIMALS 

'" I THOUGH my father and I know next to nothing about fishes from the 
■^ standpoint of systematic science, we have yet gathered, from lifelong 
observation of them in their element, in market stalls, in museums, and (pic- 
tured) in books, a trustworthy general estimate of the main characteristics 
and prevalences of their disguising coloration. As a class, they are in some 
respects the crowning vindication, or rather natural demonstration, of the 
great law of obliterative counter shading. For while in each of the classes of 
vertebrate land animals the exceptions to the employment of this principle 
are, in the aggregate, many, despite the vast preponderance of the species on 
which it is used, among fishes the exceptions are so extremely rare as scarcely 
to count at all. This is true, at least, of the fishes that live within the reach 
of daylight, as do almost all the kinds familiarly known to man. Cave fishes, 
living in absolute darkness, are blind and colorless— dull white, i. e., simple 
fish-flesh color, all over. Deep-sea fishes, though they live in perpetual night, 
are as a rule neither blind nor wholly without superficial color. They are 
sometimes whitish all over, like the cave fishes, but oftener monochrome 
gray or brown, without special shading, though sometimes marked with red. 
Thus there can be little doubt that despite the total want of daylight in the 
waters they inhabit, they habitually see and are seenl The solution of this 
enigma is the fact that the fishes and other deep-sea animals make and emit 
phosphorescent light. How generally and how largely this is accomplished 
we can judge only by the physical evidence furnished by the fishes' eyes and 
surface-colors. But it goes almost without saying that this 'home-made' (!) 

1 60 



light, by which the deep-sea fishes hunt and flee one another, is not such as 
could favor any system of obliterative shading. For it has no prevalent direc- 
tion relative to the fishes, but is erratic and forever shifting, striking all their 
sides and planes with equal frequency. Accordingly, though colored, they 
are mainly monochrome, and as dark below as above. But aside from these 
little-known fishes that inhabit the remote abysmal depths of open ocean, 
and the few kinds of blind fresh-water cave fish, practically all the species 
known to man live in water permeated by the descending light of day. 
Fishes, in fact, as man knows them, are, typically, inhabitants of the bright 
upper and outermost border of the water, just as birds and butterflies are 
dwellers in the bright-colored upper and outermost fringe of the earth. These 
normal daylight fishes may be grouped, for our present purpose, in two main 
classes,* namely, the Free-swimmers of open water, and the Haunters of sub- 
merged land. This second class is again divisible into many general types, 
whereas the first is wonderfully homogeneous and simple. Wherever the 
element of land enters into the case, there begin the chances of almost limit- 
less diversification in the adaptive development of the fishes' habits and col- 
oration. But the conditions and aspects of water alone (especially beneath 
the surface) are, comparatively, fixed, few, and simple. Correspondingly 
constant and simple is the color system of the free-swimming fishes, both 
fresh-water and marine. Their smooth, regular forms, monotonous habits, 
and single method of locomotion all work in the same direction — all lend 
themselves fully to plain obliterative coloration, founded on pure and perfect 
obliterative counter shading. The gradation of shades and tints — ^from sil- 
very-white bellies to dusky backs — on almost all free-swimming pelagic and 
fresh-water fishes, is true and delicate and exquisite beyond description. 
Among fishes of the same general form and habits, however distantly related, 
this obliterative shading varies scarcely at all from species to species. Even 
their color-tones differ but little. They almost all wear exquisite, soft, water- 

* Corresponding to the divisions called "Pelagic" and "Shore" fishes in ichthyological classi- 
fication of the fishes of salt water. 

i6i 



colors — green, olive, gray, pearl-blue, silvery, deep olive-brown, etc. These 
tints are all components in the obliterative shading and its resultant uniform, 
soft, water tone, and have, in general, little independent pattern-effect. The 
bar of silvery blue on a salmon's side, for instance, does not flash out in its 
full brilliance until the salmon, in executing some swift manoeuver, turns his 
side upward toward the daylight for an instant. At other times, in the nor- 
mal position, it is merely a link in the obliterative chain of graded shades, 
looking almost uniform alike with the salmon's actually dusky back and his 
actually white-silver belly. But any 'liquid' tinges of more vivid color 
which these iridescent areas do superimpose on the general 'flat' and mono- 
chrome effect, in the fish's normal position, help his apparent dissolution into 
his watery background of slightly mutable and varied tints. They are the 
open-water fish's markings, as it were — his pictures of vague, intermingled 
water-tints. At and near the surface, there is more variety. Bubbles, and 
foam, and flickering, shadowy ripples, seen from below — as well as dimmed 
vistas, farther or nearer, of sky and clouds and sky-lit wave tops — all play a 
part in the regular backgrounds of surface-swimming fishes, and all are re- 
peated, more or less plainly, in their fair, sheeny coloration and faint pat- 
terns. Most free-swimming, open-water fishes, indeed, spend much of their 
time very near the surface (many are even wont to leap, and a few to 'fly, 
above it — as everybody knows), and the delicate brilliance of their shimmer- 
ing water- and sky-colors is in harmony with such habits. Another important 
function of their lustrousness is the actual mirroring of water — one more 
potent factor in their wonderfully efiicient concealing-equipment. All brightly 
shiny fishes — mackerel, herrings, salmon, etc. — mirror their surroundings in 
this way. But even this beautiful principle is wholly subservient to the 
■obliterative shading, and does not upset the essential balance of its working. 

'Secant' and 'ruptive' patterns are not common among these fair-colored 
free-swimming fishes, but neither are they altogether lacking. The mackerel 
has a seamed "lateral line" which serves as a 'secant' stripe, and many 
wavy up-and-down stripes above it. A good many pelagic and fresh-water 

162 



fishes have one or more such markings, either longitudinal or vertical. But 
patterns of this sort seem less appropriate to an environment of water alone 
— ^particularly away from the surface — than to one in which there is some 
element of 'land'; and when they occur on free-swimming fishes they 
may be connected with their wearers' need to haunt the bottom during the 
breeding season. Blotchy 'ruptive' patterns are almost wholly wanting 
among these fishes. They occur, however, on a few pelagic animals of gigan- 
tic size, — namely, on certain whales — and possibly on some huge pelagic fishes 
also, though we do not know of any that are thus marked. Many of the 
giants among pelagic (free-swimming) fishes, such for instance as the sharks, 
are colored rather dingily, lacking delicate tints and lustrousness — though 
almost all obliteratively shaded to the full. 

We now come to the second and more composite class of daylight fishes, 
the haunters 0} submerged land. That is, the fishes that spend all or the 
greater part of their lives in close contiguity with submerged solid portions 
of the earth — whether rocks, sand beds, coral reefs, or muddy and pebbly 
lake and river bottoms. They are, so to speak, the sparrows and partridges 
of the water, as the free-swimmers are the gulls and swallows. More than 
this, the submerged-land-haunters are also the parrots, toucans, and para- 
dise birds of the water. Man's knowledge of subaquatic life and scenery is 
at the best pitifully inadequate, but he is able to piece out his few, fragmen- 
tary, and imperfect observations * of wild fishes in their element by an ac- 
quaintance with some indubitable general principles of their coloration and 
illumination, and by a comparison of fishes removed from the water, and in 
aquarium tanks, with terrestrial and aerial vertebrates. The conclusions 
reached by such means must necessarily be defective — ^very far from com- 
pletely rounded— but they will yet be approximately correct as far as they 
go. To the student of obliterative coloration, who has learned to perceive 
the exquisite correlations between animal and environment which prevail 
among the creatures of earth and air, the examination of such ground-haunt- 

* Subaquatic photography is destined to be of great service in this direction. 

163 



ing fishes as may come into his hands is the key to a new and strangely beau- 
tiful realm of natural scenery, which must otherwise have remained almost 
wholly unknown to him. For there can be no reason to doubt that the oblit- 
eratively shaded bodies of these fishes are covered with true pictures of their 
mysterious natural environment, so far withdrawn from human ken. Pos- 
sibly these pictures never reach quite so fine a point of minute specialization 
as do the best of those worn by birds and butterflies, for water obstructs 
sight as air does not, and the eyes of subaquatic creatures are probably cruder 
(?) organs than those of the higher land animals. Nevertheless, it is evident 
that the predaceous fishes and other subaquatic animals see keenly, after a 
fashion, and also that this fashion is not so widely different from our own, 
because in all cases where we are able to compare the pattern of a highly 
marked subaquatic creature with that of its natural environment, we find a 
beautifully true and finely detailed correspondence between the two. From 
these accessible cases alone one might plausibly infer that all highly patterned 
fishes wear real background-pictures. But to a person with artistic sight 
(i. e., sight highly and truly and roundedly developed), and an understanding 
of obliterative coloration, a glance at any such fish far removed from its home 
will leave no doubt on that score, even though the exact nature of the fish's 
normal environment remains unknown. Perhaps the most familiar among 
the ' ground '-haunting fishes that are not quite inaccessible to our study 
in their homes are some of the flat-fishes — flounders, plaice, etc. — those queer 
creatures that have departed so monstrously from the main piscine type. 
Their wonderful protective coloration has long been a matter of common 
remark; but here as elsewhere the subtle basic principle has been overlooked. 
Flounders and their kindred, using one broad side as a back and the other 
as a 'bottom,' are indeed very nearly 'flat,' and their exposed upper side 
arches but little above the surface of the sand- or pebble-bed on which they 
rest. But a close examination shows that this 'back's' very slight convex- 
ity is exactly compensated by a delicate obliterative shading, accelerated to 
cope with the sharp rotundity of the back's edges, and, downward, culminating 

164 



in the uniform whiteness of the flat underside — which serves the usual function 
of shadow-neutralizing when the fish swims about. The upper side, as is 
well known, is not only exactly like the sand or pebbles in general tint, but 
is finely peppered with lighter and darker, grayer and browner, flecks, in 
exquisite imitation of the surface of the sand bed; or it is marked with va- 
riegated pebble-patterns, or with the two kinds in combination, or with sea- 
weed colors and patterns, — as the case may be.* The sand-picturing patterns 
of these flat-fish are almost exactly duplicated by those of certain beach- 
haunting amphibious crabs. Such for instance is the exquisitely dainty and 
elusive little "Spirit Crab" of the American tropical and subtropical coasts. 
This little crab dwells in myriads on the flat sandy beaches of the West In- 
dian Islands, etc. ; but its obliterative shading, sand-color, and sand-picturing 
pattern are so potent that it is next to impossible to see it until it moves. Even 
then it is inconspicuous enough, though it runs with great speed. Aquatic 
crabs which haunt submerged rocks are marked much like the fishes inhab- 
iting like situations. Those of northern seas are as a rule not gaudily colored, 
although often richly marbled and spotted and streaked with accurate rock- 
picturing patterns, founded always on full obliterative shading. Some of 
these rock-patterns, particularly those of fishes, are almost as minutely accu- 
rate as those worn by certain warm-blooded land creatures, such as the 
Nighthawk (Chapter V, Figs. 30-31). As the Nighthawk's pattern contains 
an admixture of the picturing of lichens and other small and delicate dry- 
land vegetable forms, so the rock-surface patterns worn by fishes contain 
generalized pictures of seaweed, minute moUusca, etc., — as it were the rock 
lichens of the water. But whereas in cold and temperate seas this superficial 
growth is comparatively scanty, often allowing the actual surface of the rock 
to show, in tropical waters it tends toward a completely masking luxuriance 
and oi-nateness. Particularly is this the case in coral regions. The fishes of 
tropical coral-shores and reefs are almost as famous as tropical butterflies 

* The rays (Raiidm) have much the same general system of coloration as the flat-fishes, though 
usually wanting the minute adaptive markings. 

165 



for gorgeous brilliancy of coloration and variety of pattern. This gaudiness 
of tropical fishes, so far from being, as most people have supposed, a mere 
lavish expenditure of ornamentation, on Nature's part, is merely one more 
beautiful evidence of universally perfected obliterative coloration. As the 
sunlit crown of the tropical forest is full of gaudy colors, so, and more so, is 
the sunlit upper region of tropical ocean water, about coralline and rocky 
shores and reefs, and white sand beds. What could be more natural and 
appropriate than that the fishes living in such places should have, in addi- 
tion to their never-failing obliterative gradation of general shades, intensely 
brilliant colors, in rich and varied patterns? All the 'paradisaic' tropical 
fishes, which have so often been marveled at, are in fact merely covered 
with average-background-pictures, working for their wearers' concealment 
as truly as do the dull-colored and delicate patterns of the flounders and 
northern rock fishes and rock crabs. To be sure, the background-pictures 
worn by these 'submarine butterflies' are as a rule very much generalized, 
for there is redundant variation in their surroundings, and some of them are 
restless vagrants, — though seldom going far from the rocks or coral-beds. 
Doubtless there are many kinds that ''lie close," and never wander far, — and, 
accordingly, are equipped with more minute and definite pictures of gay cor- 
alline and weedy backgrounds. But here our knowledge (i. e., that of the 
present writers) is defective. Nevertheless, the kinds and degrees of oblit- 
erative color- and pattern-adaptation among tropical fishes, even as we know 
them, are many and various — too many and too various to be described in 
detail here. A few more very general statements about them must sufiice. 
Their colors (besides black and white, and all the mixed tints of gray and brown 
and olive) include the entire range of the spectrum, — ^red, yellow, blue and 
green being perhaps the commonest, among pure colors. These, of course, 
are the colors of coral, seaweeds, moUusks and other lowly marine animals, 
and of water over sand and stones, — or, in other words, colors typical of the 
fishes' environments in fertile tropical seas. The above-named tints, with 
very many more, occur on the fishes in all sorts of striped, banded, spotted 

1 66 



and blotched patterns, whose effect is 'secant,' 'ruptive,' or purely and del- 
icately background-picturing, as the case may be. Iridescent or highly change- 
able color is not so characteristic of these gaudy ground-haunting fishes as it 
is of the free-swimmers that spend much time very near the surface. Indeed, 
their brightest colors are often almost lusterless— like those of toucans and 
parrots rather than those of hummingbirds and peacocks. This, also, is in 
evident harmony with their ways and places of life. For, down in ocean 
water, below all the surface-agitations, the light is constant and somewhat 
diffuse, and plays few tricks of any sort; hence strong 'dead' color, in fit 
background-patterns, is all that is required to complete the concealment of 
obliteratively shaded fishes when they lie motionless in that quiet realm. 
Sorne of the most elaborate and beautiful of the obliterative patterns worn by 
such fishes are on the fins, particularly the dorsal and the caudal. When the 
fins are extraordinarily long but unmarked, as for instance in the genus Chato- 
don, they sometimes bear a direct mimetic resemblance to blades of seaweed. 
Mimetic in a similar way are also, probably, some of the tentacular excres- 
cences of fishes — such as those of the "Angler" or "Hunting Frog" (Lophius 
piscatorius, etc.). Indeed, the whole lumpy form of this sluggardly "angler" 
suggests mimicry of a weed-grown rock or lump of coral, and its obliterative 
shading is, I believe, scanty or wanting. There may, indeed, be a good 
many cases of true mimicry among the fishes of grotesquely distorted form; 
but we have no definite knowledge of more than one or two. On the other 
hand, it seems that most of their excrescences and lengthened, 'painted' 
fins are, like the corresponding developments of birds, truly obliterative, and 
cooperant with full counter shading. The two uses however, are of course 
constantly intervolved. Some of the pipe-fishes, and other . snake-shaped 
haunters of floating seaweed, probably bear a mimetic resemblance to flat 
weed-blades. But being themselves cylindrical, they cannot look flat without 
the aid of obliterative shading, which, accordingly, is here used for the attain- 
ment of a mimetic effect. (This is a common occurrence among lepidopter- 
ous larvae, as we shall show in a later chapter.) 

167 



In addition to all the wonderful devices of 'fixed adaptive color and pattern 
worn by fishes, they have often the extraordinary gift of 'chameleonism,' 
i. e., quick, sometimes instantaneous, color-change. Indeed, some of them 
have this power in a higher degree than any other vertebrate animals known 
to man, their coloration being as it were 'alive,' and 'fluid' — darkening 
and brightening, and shifting its pattern, in swift, repeated mutation. Some- 
times the changes are evoked only, or chiefly, by changes in the light which 
strikes the fish's surface. But no doubt the chief use of such changeableness 
of coloration, in most cases, is adaptability to various backgrounds. The 
fishes most subject to such 'chameleonism' are the gay-colored 'ground- 
haunters' of tropical seas, — the very ones that are notable for their lack of 
iridescence; — but trout and probably other fresh- water fishes are also some- 
what 'chameleonic' Mr. A. R. Dugmore, in his admirable and delightful 
book on Nature photography ("Nature and the Camera"), gives some inter- 
esting testimony on the subject. He, moreover, fully and clearly states the 
fact that even the gaudiest tropical fishes are colored for concealment. But, 
like all the rest, he ignores the great basic principle of obliterative counter 
shading, without whose aid the color adaptation would be of so little avail. 

So far we have considered mainly the fishes of salt water. But of course 
the same general principles, with various small modifications, apply to fresh- 
water fishes — the inhabitants of lakes and brooks and rivers. Some of those 
I have already mentioned, such as the salmon and the herring, live in both 
kinds of water, making annual migrations from the one to the other and back 
again. These are all of the free-swimming type — ^with colors and markings 
not specialized to match any one sort of ground, but rather adapted for gen- 
eralized wa/er-picturing near the surface. This, the type of coloration of the 
generality of free-swimming "pelagic" fishes, is also, with modifications, that 
of the free-swimming fresh-water kinds — much more localized in habitat 
though they almost always are. Inland 'bottom-fish,' also, are much like 
marine ones, though with less variety of coloration. Some of them are ' mud- 
fishes,' and colored muddy brown or gray, with full obliterative shading, 

1 68 



but usually with scanty markings. Soft, dull mud, more or less barren of 
vegetable or stationary animal life, and free from stones and sand, is a char- 
acteristic fresh-water product. Such fish as the American Hornpout (Ami- 
urus catus, etc.) haunt this simple element, and have a correspondingly plain 
and simple obliterative equipment. So do the fish-like young of many frogs 
and toads and salamanders^the "tadpoles," in other words. But, as in 
almost all other cases, there are gradations from this type of coloration into 
others. The common American Brook Trout (Salvelinus jontinalis) varies 
much in coloration, having even, as I have already mentioned, a 'chamele- 
onic' power of almost instantaneously changing — ^lightening or darkening — 
its general tint. The dullest-colored trout from a dark, muddy pond or brook 
is only a few grades above the hornpout or the poUiwog in -fairness of tint 
and elaborateness of pattern; while a light and bright one from a clear, shallow 
stream is one of the most exquisitely and 'specially' marked and colored 
of fishes. In the aspect of this fair trout's common background there is a 
characteristic which we have not yet considered, and which in its full display 
is peculiar to shallow running water. That is, the system of moving light- 
and-shadow patterns on the bottom, made by sun-rays variously refracted 
from the agitations of the surface. Everybody is familiar with these beauti- 
ful water-patterns, that glide and flicker over the beds of brooks in sunlight. 
They are of many forms, as the surface-agitations are of many sorts; never- 
theless one can distinguish a few predominant types among them. The sim- 
plest consists of more or less nearly parallel and widely separated undulant 
bright lines; the most complicated is a maze of twisting, branching, tremulous 
bright bands encircling darker spaces — plaided, sometimes, like the scales 
of a fish,— or like the giraffe's pattern. These pretty effects are produced of 
course both by wind- and current-ripples; but it is the cwrrewZ-ripples that 
make the greatest variety of patterns. Notable among these variations are 
the whirlpool shadows. They are cleanly and perfectly circular dark spots, 
each surrounded by a bright rim of sunlight. In all brooks whose passage 
is in any way obstructed at the surface, little whirlpools are engendered here 

169 



and there, which glide down with the current till they flatten out and vanish. 
When the sun shines, each of these little whirlpools as it glides along is ac- 
companied on the bottom by its round, gold-rimmed shadow. Often these 
pretty spots may be seen trailing along in companies, and some stretches of 
brook-bottom are always thickly speckled with them — appearing and gliding 
forward and fading out in quick, ever-recurrent succession. Next to the 
wavy, gold-laced ripple-patterns, this whirlpool-spotting is probably the most 
universally characteristic element of the appearance of brook-bottoms in 
sunlight. Nor are whirlpools the sole producers of this effect. Any little 
pits in the surface of the water, such as are made by barely-floating specks 
of debris, or by the lightly planted feet of water-skippers (Hydrobatidce), cast 
the same sbrt of gold-rinimed shadows, though seldom in such bright, con- 
spicuous show. These several so characteristic brook-bottom patterns might 
be expected to occur in the background-pictures worn by brook-haunting 
fishes. Nor have we to seek beyond the common American Brook Trout 
(Salvelinus jontinalis) to find both wavy ripple-shadow patterns and circular 
whirlpool-patterns in full application. The little, light-rimmed dark spots, 
the familiar "trout spots," are 'painted' on the fish's side, above and below 
the "lateral line," and the wavy marks along the whole extent of his back 
and on his dorsal fin. 

There is much likeness to the 'whirlpool' spotting in the exquisite water- 
patterns worn by certain seals (as, in some pelages, the Common Seal, Phoca 
vituHna), which are also wholly fish-like in their smoothly graded obliterative 
shading, and the general character of their coloration. But we do not know 
enough about their habits and environment to say much about the special 
functions of their markings. Other seals, again (i. e., the Bladder-nose, 
Cystophom cristata), are marked, over full obliterative shading, almost ex- 
actly like certain sea-fishes. That is, they are irregularly dabbled and flecked 
with black and white and gray, in what seems to be a generalized rocky (and 
weedy?) bottom-pattern, as seen through several feet of water. Among fishes, 
like patterns are worn for instance by some cod. There is certainly great sig- 

170 



nificance in this superficial likeness between animals so remote from one 
another, fundamentally, as seals and fishes, which yet live much of the time 
■under common conditions, and have somewhat similar outward forms. Their 
superficial resemblance is all the more notable in that the like colors and 
patterns are produced in totally different ways in the two cases, those of the 
fishes being in the skin, and those of the seals made with minute external 
hairs. On the other hand, this is no more remarkable than the many familiar 
cases of superficial resemblance among widely different land animals which 
have acquired kindred habits of life — e. g., some hummingbirds and hawk- 
moths. 

To sum up the main facts about the disguising-coloration of fishes, 
as far as they are known to us: All 'daylight' kinds are obliteratively shaded, 
with the possible exception of a few mimetic forms; while their particular 
adaptive developments of color and pattern correspond to those of birds 
and lizards and butterflies on land, and are almost — perhaps quite — as highly 
and beautifully diversified. But about the exact nature of these special adap- 
tive costume-developments of fishes, little is yet known. The subject's very 
inaccessibility lends it an exceptional fascination, and it must ultimately receive 
the profound and detailed study it deserves. 



171 



CHAPTER XXIV 

REPTILES AND AMPHIBIANS 

GAUDY and motley-colored almost as the brightest birds, butterflies, and 
fishes, are some of the arboreal lizards and snakes of tropical forests. 
The lizards are wonderfully light and agile climbers, wanting only wings * to 
give them full command of the regions of airy outermost foliage, into which 
they freely penetrate; while the most truly arboreal snakes are scarcely less 
gifted acrobats, and spend much time in those realms of richest color. With 
both snakes and lizards, green is the commonest color; but red, yellow, orange, 
blue, etc., frequently occur on them, in various sharp 'secant,' 'ruptive,' or 
generalized background-picturing patterns, exactly corresponding to those of 
the birds inhabiting like regions, though differently modified to suit the lizard's 
and especially the snake's very different bodily forms. The prevalence of 
green in their costumes, also, is paralleled among birds, for, as we have seen, 
the 'lower tier tree-top birds' of the tropics tend to be green; and the strictly 
arboreal reptiles have almost the same local habitat. 

Both snakes and lizards, and the bright-colored arboreal kinds as well as 
those of duller tint and humbler situation, are almost without exception obliter- 
atively shaded, to the full,f and this obliterative shading is almost wholly 
essential to their concealment. As a snake has the simplest bodily form of 
all vertebrate creatures, so is his obliterative shading, when complete, the 

* A few kinds (the "dragons,'' Dracho) have even parachute wings, like the flying squirrels. 

t Partial exceptions occur among the burrowing snakes and legless lizards, some of which have 
almost monochrome surfaces, and among sea snakes. They, however, have obliterative shading in 
gross, being dark above and light beneath, but with the two shades sharply contrasted instead of 
connected by intermediate tones. In this they resemble certain whales. Whether or not all the 
species of sea snake are colored thus crudely, I cannot say. 

172 



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PLATE XI 




AKOEMBjQo BJUJIM 



most beautifully simple to be found among vertebrates, not excepting fishes. 
There can be no finer display of this great principle in full and pure applica- 
tion than is furnished by the common green Grass Snake {Liopeltis vernalis) 
of northeastern North America. (See Fig. 121.) Deep grass-green along the 
upper median line, his color shades lighter by imperceptible gradations down 
his sides, passing through pale straw-green along the edges of his ventral 
surface, and culminating in dim greenish white on the flat underside. The 
effect of this exquisite shade-gradation is to make the little snake appear of a 
uniform, intangible, grassy green, when he lies at rest or glides along, on the 
ground or in the bushes, in his normal position. Turn him over, so that his 
pale belly is uppermost, and he becomes very conspicuous — looking grossly 
solid (Fig. 122). He is still, on the whole, green, like his surroundings — 
but by no means 'obliterated.' (!) In a normal position, 'flattened out' 
completely by the counter shading, the snake is not only likely to look merged 
into his general green background of grass (or other vegetation), but, when 
this illusion fails, and parts of his surface definitely catch the eye, they will as 
a rule pass for portions of broad grass blades or flat leaf-surfaces. This is 
mimicry, after a fashion, but it is mimicry achieved only with the aid of obliter- 
ative shading — and the effect is decidedly of minor importance. Such im- 
minglement of the two principles ('obliteration' and mimicry) occurs much 
more pronouncedly among lepidopterous larvae, which we shall describe in a 
later chapter. In the case of the little green snake, the intrusion of the semi- 
mimetic effect is due to his complete lack of markings. Any markings, super- 
imposed on so perfect a counter shading, would almost infallibly look as if 
they belonged to the background, thus clinching the obliteration. But simple, 
immaculate coloration, with full obliterative shading, is very common among 
snakes. In fact, it is about the conmionest, as it is the simplest, type of ophid- 
ian coloration, both among terrestrial and arboreal species. Most of the 
snakes thus colored are swift and active kinds that seek and chase their prey 
instead of lying in wait for it. The gliding motion of their long, slim bodies 
would often be revealed by markings, in cases where without them it might pass 

173 



unnoticed. This is true especially of transverse marks. Lengthwise marks, as 
has been explained in an earlier chapter, are much less conspicuous on a moving 
object than those in any degree transverse. Stripes running the whole length 
of the body, such as are worn by certain snakes, add nothing to the conspicuous- 
ness of motion,* and in fact tend to lessen it, inasmuch as they split their 
wearers' forms, so to speak, into narrow, parallel lines of different colors or 
shades, some of which are likely to match the moving reptiles' backgrounds. 
Markings of this kind also, are, I believe, almost wholly confined to swift hunt- 
ing-snakes. On the other hand, although some snakes by no means sluggish 
are transversely ringed (e. g., some of the coral snakes), yet markings of this t)rpe 
characteristically belong to species which spend most of their time at rest, and 
often or habitually lie in wait for their prey. Such markings, indeed, are as 
particularly well fitted to conceal a motionless snake as they are ill fitted to lessen 
the conspicuousness of one in motion. For, aided by background-marks of like 
aspect and direction, they 'cut up' the motionless snake's long form into short, 
un-snake-like segments. Lengthwise stripes, under the same conditions, have 
merely the effect of ' splitting ' their wearer's form into several narrow but snake- 
like parts. So also many of the lizards that persistently "lie close" have bold, 
transversely 'secant' bands. Such are most of the iguanas, and a great many 
smaller species, both arboreal and terrestrial. Even the ' oilcloth '-plaided 
pattern of the sluggish Gila Monster (Helodermata) is transverse rather than 
longitudinal. More or less transverse also, though minutely varied and elabo- 
rated, are the beautiful and terribly effective ground-picturing patterns of 
such sedentary poisonous snakes as the Rattlers and the Copperhead (Cro- 
talus and Trigonocephalus). (See Fig. 123.) The Copperhead's pattern is 
especially remarkable. As the reader will see by looking at Plate XI, it pic- 
tures with astounding accuracy heaped dead leaves, with their lights and 
shadows. This wonderful resemblance, like the rest, owes its power primarily 
to the underlying or inwoven counter gradation of shades, whereby the snake's 
cylindrical solid form is visually 'flattened out,' and prepared for complete 

* (i. e., of longitudinal motion) — A. H. T. 
174 




Fig. 121. 




Figs. 121-122. Green 
Snake (IJopelUt ver- 
nalis), right-side-up 
(Fig. 121), and up-side- 
down (Fig. 122). Crhe 
iiormaUy placed one- 
Fig. 1 2 1— however, is 
very poorly lighted for 
'olillteration'.) 




^f1^ ^^n The Burroundines of this Kattlesnake have been madewhollyby copying the snake's own color-'valnes,'— by perceiving what 
scene he represents, and using each one of his 'notes' for the right detail of the scene. The result is an astonishingly true rendering of 

the 5}^* ^gt„re^i"k" ^veral others in the book, shows that animals' normal environments may be exactly deciphered from their coloration. 



obliteration by means of background pictures. There are many other types of 
ground-picturing pattern, more or less elaborately developed, among terrestrial 
sedentary snakes. That of the loathsome and beautiful African Puff Adder 
(Clotho arietans) is a good example of the desert type, which numbers many 
species, both of snakes and lizards. The PufE Adder, and all of his kindred 
which bear equally minute sand-pictures, are to the highest imaginable degree 
fitted for "lying close" — more so, perhaps, even than such a wonder as the 
Copperhead. Lizards^ picture-patterns do not often reach quite such minute 
finish, a:nd this is in keeping with the fact that almost all lizards are quick and 
agile. Most kinds, though they may "lie close," are yet always ready to resort 
to sudden and swift dashes in case of pressing danger; and they often catch their 
prey by long leaps or even running chases. The picture-patterns of lizards ac- 
cordingly tend to be more generalized and crude than those of snakes, but there 
are of course many exceptions on both sides. Some tree-bark patterns of 
arboreal lizards, for instance, are perhaps as highly specialized as any snakes' 
patterns. (See Fig. 124.) Lizards, furthermore, have in many cases the won- 
derful power of sudden color-change, or 'chameleonism,' which is, I believe, 
wholly wanting among snakes. This phenomenon, mentioned in the last chap- 
ter, is too well known to need detailed comment here. Suffice it to say that the 
various adaptive costumes which the lizards assume and doff are practically all 
and always equipped with full obliterative shading, and often with highly- 
wrought background-pictures. (See Appendix A.) 

One more type of marking among snakes calls for especial mention. That 
is the sylvan sun-and-shadow or 'leaf -checker'* pattern worn by some of the 
big tree-boas and pythons. This type of pattern and its uses have already 
been described at some length in Chapter XXI, in connection with leopards, 
giraffes, etc. On snakes its form is somewhat different, as the reader will see 
by an examination of the bits of boa pattern shown in Fig. 120, but the general 
effect is much the same. Indeed, the resemblance in pattern between some of 
these bits of boa and some of ocelot (Fig. 120), is close. 

* (and hole-picturing) — A. H. T. 



Mimicry, in the sense of the counterfeiting of single inanimate things, seems 
to play but a very smaU part in the coloration of snakes and lizards, whose 
disguising costumes are almost always obliierative, purely and simply. In fact, 
we do not know any positive cases of such mimetic equipment among reptiles, 
beyond the fragmentary sort mentioned in connection with the Green Snake. 

Crocodilians — that is to say, crocodiles, alligators, and gavials — ^have not 
very highly specialized protective coloration. Mud-colored, armored, and 
unmarked, — comparatively speaking — they yet have counter shading, which 
tends to 'obliterate' them, in the water and on land. Often, however, they are 
so placed as not to be 'obliterated,' but plainly to show their great, hulking 
forms. Then their irregular, lumpy outlines often serve to make them pass 
for logs or stones. Unquestionably, they often present, either wholly or in 
part, a mimetic resemblance to such objects. An alligator swimming or rest- 
ing at the surface shows above water only his snout, his eyes, and sometimes a 
portion of his back — three or four gray-brown lumps which look, to any but the 
most experienced eye, like points of rock, or projections of a submerged log — 
■or cypress "knees." However casual, all such resemblances must be of service 
to the alligator.* Such an animal's more or less mimetic likeness to his inani- 
mate surroundings is often increased by the sticking to his heavy, muddy back 
and sides, when they are out of water, of bits of vegetable rubbish. This is 
the case also with some of the great fresh-water tortoises, whose concealing- 
coloration is at least as simple as the crocodilians. These tortoises even have 
algae and various mosslike, lowly water-plants growing on their shells, and 
some have dermal appendages which look like such plant-growths. For the 
rest, they are obliteratively shaded, and more or less mud-colored. The gigan- 
tic land tortoises, such as those of the Galapagos Islands, have even less to 
show in the way of protective coloration. With no obliterative shading worth 
mentioning, and no markings, they wear, it would seem, merely the simple, 
organic colors of old, weather-beaten shells and wrinkled hides. Fruit- 

* In furtherance of offensive operations. For the brutes are the kings of the waters they inhabit, 
and have — at least when they are full grown — scarcely any predaceous enemies. 

176 



eating, huge, slow, mild, and immune from enemies, they have, apparently, 
little need of adaptive coloration of any sort. The sea turtles, some of them 
of almost equally great size, have decided obliterative shading, and some- 
times — particularly on their upper shell or "carapace" — obliterative pat- 
terns. The Hawksbill ("tortoise-shell") Turtle (Eretmochelys imhricata), 
for instance, has, as everyone knows, a beautifully marbled carapace. This 
pattern is obliterative, being, no doubt, a generalized sea-ground-picturing 
pattern, like that of many fishes, crabs, etc. Kindred patterns of the cara- 
pace are worn by certain small fresh-water and land tortoises — such as the 
"box turtle" (Cistudo Carolina), of eastern North America; Two small fresh- 
water tortoises of the same region are particularly notable for bright color 
and clear pattern, namely, the common "mud turtle" or Painted Tortoise 
{Chrysemys picta), and the little yellow-spotted brook tortoise (Clemmys 
guttata). The Painted Tortoise has complete obliterative shading of shell, 
head, legs, and tail, ajid, in addition, beautiful obliterative markings on almost 
all his exposed skin, and on his carapace, especially along its edge. Those 
on the top of the blackish carapace are olive green, and narrow— mere 'mar- 
ginal bands,' bordering the plates — the rest are red and yellow, in the forms 
of spots and broad streaks, on a dusky ground. These brighter markings 
look like bits of rich-colored water weeds, above or below the surface, like 
certain water and marsh flowers, like sun-flecks on the muddy bottom, and 
like various other common details of pond and stream scenes. (Compare the 
bill-colors of the Wood Duck, described and pictured in Chapter XI.) In 
conjunction with the obliterative shading, and the general effect of dark water 
and mud-color achieved by the head, legs, tails, etc., on which they occur, 
these bright markings must often admirably serve as obliterative picture-pat- 
terns. The under-shell or "plastron" of this turtle is immaculate light yellow- 
buff, while a connecting shade between it and the dusky carapace is furnished 
by the red-marked side-band of shell, and the similarly colored down-turned 
edge of the carapace itself. The little brook tortoise (Clemmys guttata) has 
the same general type of coloration, with many minor differences. Its bright 

177 



markings are all yellow, and mainly in the form of smallish circular spots, 
which are scattered over the whole black carapace as well as over the fleshy 
parts. On the head and neck and fore-legs some of them are lengthened out 
into streaks. The plastron is buff -colored, but marked with big, irregular black 
blotches — a pattern and coloration highly characteristic of the small American 
tortoises. The obliterative effect of the circular bright-yellow spots is much 
the same as that of the Painted Tortoise's richer pattern; but the little yellow 
disks are more aptly suggestive of spots of sunlight on dim brook-bottoms. 

To sum up the foregoing fragmentary account of chelonian coloration: 
Most turtles, aquat-ic and terrestrial, are obliteratively shaded, and, in a gen- 
eral way, obliteratively colored; but comparatively few of them have highly 
specialized obliterative picture-patterns. 

We now come to Amphibians, the last of the vertebrate classes we have 
to consider. These, unlike tortoises, are for the most part soft, weak-skinned 
animals, living much exposed to danger, and being much preyed on by ra- 
pacious creatures. Accordingly, their disguising coloration has been highly 
and variously developed. Most variously, indeed, as their habits are ex- 
tremely various ; yet the principles we have already studied cover all the vari- 
ations. In their larval state, as "polliwogs," "tadpoles," etc., these animals 
are all more or less fish-like, both in habits and appearance, and their oblit- 
erative coloration does not then differ essentially from that of certain mud 
fishes (Chapter XXIII, p. 169). But in the perfect state the various types 
become highly differentiated both from other animals and from one another. 
How many and diverse, for instance, especially as regards disguising-colora- 
tion, are the types of frog and toad! Even if we confine ourselves to those 
of temperate North America and Europe (as we, personally, are obliged to 
do, because of our ignorance of the no doubt far more diversely specialized 
tropical forms), the essentially different types are many. First, there are 
the aquatic frogs, as the common Green Frog and the great Bullfrog of North 
America (Rana clamitans and R. catesbiana), etc. Then the terrestrial wood- 
land frogs (Rana sylvatica, etc.), colored like some delicate forest ground- 

178 



bird; then the semi -terrestrial grass-haunting frogs {Rana palustris, Rana 
virescens, etc.). Then, again, the terrestrial toads, aquatic only during the 
breeding season, and otherwise fitted for life on and under comparatively 
dry and open ground; then the little, tight-folding tree toads {Hyla, etc.), 
modified both in form and color for concealment on perpendicular reed-stems, 
on sticks and twigs, or on tree trunks and on rocks, as the case may be. The 
Common Tree Toad {Hyla versicolor) of eastern North America, is a good 
t5^e of this remarkable group. It is a tree-bark haunter, veritably moth-like 
in the exquisite minuteness and accuracy of its tree-bark pattern, and gifted 
in a high degree — as many amphibians are in less degrees — with 'chame- 
leonic ' powers of rapid color-change. 

Different as are the various batrachian types above named, both in habits 
and in superficial aspect, they all have much in common even in their color- 
ation. For they are all obliteratively shaded, delicately and fully, and the 
concealment of all of them depends primarily on this same great principle. 
Those which cling to tree trunks are, of course, lighted as are woodpeckers and 
other scansorial birds (Chapter VIII) — that is, almost like the ground ani- 
mals — and hence are similarly counter shaded. The little reed-toads and 
twig-toads, folded up tight and smooth and narrow, and clinging close to 
the tree-branch or reed-stem, are likewise 'blended into' the surface of their 
perch by aid of their obliterative shading. But of course this is the case 
only when they are seen in back view. In profile, they may still be and often 
are 'obliterated,' being indistinguishable from whatever forms their back- 
ground; but their lack of markings (a trait characteristic of some kinds, par- 
ticularly green ones) hinders this effect, and must often cause their contours, 
thus relieving, to be visible. Here mimicry comes into play; for their bodies 
are so modified in form, and held in such positions, as readily to pass for 
mere slight excrescences of the plant-surfaces on which they are sitting. There 
may even be species whose whole disguising equipment is thus mimetic, 
to the exclusion of obliterative shading. But, with or without these 
possible few exceptions, the protective coloration of batrachians is preem- 

179 



inently obliterative, like that of all the other vertebrate orders we have 
considered. 

Most beautiful and minute, as I have said, is the picturing of lichen- 
flecked bark on the backs of the obliteratively shaded and 'chameleonic' 
tree toads — e. g., Hyla versicolor. Equally effective and more remarkable 
is the picture-pattern of some grass-frogs. This pattern is closely akin not 
only to the grass-patterns of certain birds (see for instance the ptarmigan in 
Fig. 41, Chapter VII), but to that worn by some ground-perching moths, 
which will be described in a later chapter. It pictures dim, grassy ground- 
shadow overlaced with crisscrossing bright-green grass blades. The picture, 
moreover, is one of unusual deceptive power — as everybody will agree who 
has tried to catch these frogs amidst luxuriant grasses. Though the species 
is of course not wholly confined to such grassy spots, its coloration fits them 
far more closely than it fits any other sort of ground. As is almost needless 
to say, obliterative shading is here, as in all kindred cases, the basis of the 
obliterative effect. The more aquatic and mud-haunting frogs have perhaps 
less highly specialized, but doubtless perfectly adapted obliterative coloration. 
The greens and browns of shore-weeds, of still, stagnant water, of water re- 
flecting the green shore, of mud and sticks and water-soaked dead leaves — 
such are the prevailing colors of these frogs. These tints are arranged, more- 
over, in a system of complete obliterative shading, culminating usually in 
yellowish white on throat and belly. The independent patterns they form 
are more or less obscurely-mottled, but adequately serve as generalized pic- 
tures of the frogs' rather various muddy and watery backgrounds. Dull 
black shadow-color is an important factor in these patterns. But neither 
water-shine flecks of the brighter sort, nor bright brook-bottom sun-flecks 
occur in them, so far as I know. Somewhat more specialized, again, is the 
picturing of the leafy forest floor on certain woodland frogs, such as the pretty 
little Rana sylvatica, already mentioned. (See Figs. 125-126.) Small as 
this frog is, he yet wears two or three fairly definite leaf-edge-against-shadow 
pictures, on his delicate pearl-"brown and dusky, obliteratively shaded 

180 





Fig. 124. Brown Lizard (Kentucky) on the tnink of an apple tree. 
Photographed from life by George C. Embody. 



Fig. 127. Common Garden Spider on its web. Obliter- 
ative patterns and obscure gray head, with a glaucous 
web-trail made to match it. 

Photographed from life by Dr. K. W. Shufeldt. 





Figs. 125-126. Brown 
Wood-Frog among dead 
leaves and pine needles. 
Delicately-detailed leaf- 
picturing pattern, based 
on perfect counterehad- 
ing. (Notice the shadow- 
picture on the frog's 
cheek below the eye, 
bordered on its lower 
side by a sharp light 
streak, which in its turn 
has a narrow inferior 
dark border, and per- 
fectly represents a leaf- 
stem, pine needle, or 
shai-p leaf-edge, with its 
shadow. 

Photographed from life, 



coat. Though he is partially aquatic, like all his kindred, his colors are more 
particularly suited to the time when he is out of water, and when, no doubt, 
he is in more danger of being snapped up by predators. On the other hand, 
his coloration is to some extent 'chameleonic,' and interadaptable to various 
environments. 

The common ground toads {Bujo) are more nearly terrestrial than any 
of the frogs we have considered; but even they spend the breeding season 
in the water. Characteristically, however, through the greater part of their 
waking life, these toads are inhabitants of ground where there is exposed earth 
or sand; and their coloration seems most closely to fit such spots. But it is 
also well suited to dead-leaf-strewn ground, or any other sort of brown, mi- 
nutely mottled earth surface. Founded on full obliterative shading, their 
richly and delicately speckled picture-patterns, of various browns and grays 
and duskies,* nearly approach the minute specialization of those worn by 
goatsuckers and other ground birds. By far more sluggish than the mud 
frogs (at least during the day — for they are nocturnal), and allowing enemies 
to approach more closely, these toads are equipped, as one would expect, 
with more highly finished obliterative coloration. Their warts — what- 
ever may be their other uses — are effective agents in the background- 
picturing. 

Cruder 'ruptive' patterns seem to be almost wholly wanting among batra- 
chians, — or at least among the tailless batrachians of temperate North America 
and Europe. 'Secant' patterns of various kinds occur among them (see 
Chapter XIII, p. 78), but usually, or perhaps always, they are also definite 
features of the picture pattern— looking like a grass-blade, or a stick, or a leaf- 
edge, or a gleam on shiny mud. 

The tailed amphibians — newts, salamanders, axolotls, sirens, mud-pup- 
pies, etc. — are lowlier than frogs and loads, not only in their general make-up 

*The common American toad {Bufo americanus) and the European "Natterjack" toad {Bujo 
calamita) are good examples of this type. But not all ground toads are thus colored; witness the 
Green toad (B. viridis) of continental Europe. 

181 



but in their disguising-coloration, which presents few or no new or particularly 
noteworthy features. They are almost all obliteratively shaded, and wear 
colors and markings which tend to make them invisible against their normal 
backgrounds ; but few of them show a very high development of special adaptive 
coloration. Some terrestrial kinds, living in rotten logs and stumps and be- 
neath dead leaves, are extremely gaudy — wearing much bright blue, green, 
purple, or sometimes red. But if we learned more about their habits, we 
should probably discover some remarkable protective use of these bright 
colors. They are usually brightest on the tail — sometimes confined to it — 
and this suggests that they may serve the salamanders in the same way that 
the banded tails of pheasants, etc., evidently serve these birds (see Chapter 
XVII) — that is, as baits or targets, to make their enemies strike behind (when 
they are running) and miss the vital parts. This supposition is in fact ex- 
tremely plausible, inasmuch as the tails of such amphibians, like those of many 
lizards, are easily detachable, at any point, and are often left writhing in the 
grasp of enemies, while the vital fore-parts to which they belonged escape. 
Other terrestrial salamanders are marked with brown and brownish red — 
dead-leaf and rotten-wood tints — and with dusky shadow-tones, in lengthwise 
' secant' stripes. Others have transversely secant markings, and some are 
rather brightly pied with black and whitish, or yellow. Others, again, 
are marked with neat, circular spots of yellow, on a black ground, like the 
little tortoise described on page 177, but with the spots proportionately much 
larger. We, personally, know too little about the habits of these various species 
to speak with confidence about the special adaptive fitness of their markings. 
The coloration of the aquatic species corresponds more or less closely to that 
of fishes. Some have pronounced obliterative patterns, picturing mottled 
pond-bottoms, etc.; but the disguising coloration of many of them is very 
obscure. 

We have now finished our skimming survey of vertebrates. The remaining 
three chapters will deal with crawling and flying invertebrate creatures. 

182 



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CHAPTER XXV 

CATERPILLARS 

THIS is an immensely interesting branch of the subject.* The existence 
of most naked lepidopterous larvae is singularly dependent on protective 
coloration, owing to the fact that they are the favorite prey of many kinds of 
birds, and, living exposed to view on leaves, are also incapable of rapid motion. 
This universality of the extreme need of concealing coloration among hairless, 
leaf-eating larvae, and the enormous number of their species, whose many and 
diverse food plants, feeding habits, sizes, and fundamental structural shapes 
call for an almost equally great variety of devices for the achievement of their 
protection, makes the study of them peculiarly fruitful, as well as intricate 
and difl&cult. Indeed, the subject is so vast, that no one, even if he devoted 
years exclusively to it, could hope to discover and appreciate more than a small 
fraction of the whole number of diverse but equally fine and remarkable pro- 
tective-coloration developments of the larvae of a single wooded region. 

In the plates which follow, we show merely the pick of a small collection of 
paintings and sketches made during two autumns largely devoted to the study 
of caterpillars (and spiders), chiefly in southwestern New Hampshire, U. S. A. 
Few and imperfect though they are, they yet illustrate fairly well several princi- 
ples which are of primary importance. We have confined ourselves almost 
entirely to hairless larvae, because highly specialized protective coloration 
plays a much larger part among them than among the hairy ones. This is 

♦(Historically, it is especially noteworthy as being the branch in which Prof. Edward B. Poul- 
ton, of Oxford University, made his independent and earlier partial discovery of the law of Oblit- 
erative Shading. At the time, however, he did not realize that the law had a wide application, even 
among lepidopterous larvae, and his subsequent original investigations of protective coloration have 
been largely in the field of mimicry. See, however, the quotation from Nature at the close of our 
first chapter.) 

183 



most natural, as naked larvae are far more acceptable to most insect-eating 
birds, and the very hairy ones are to a large degree protected by their hairs 
alone, and have much less need of deceptive coloration. (It should be noticed, 
however, that, whether by coincidence or not, certain hairy larvae bear a strong 
mimetic resemblance to details of their environment. Thus some of the furry, 
white or yellowish grass-caterpillars look wonderfully like the fuzzy flower- 
heads of the grass on which they feed, or of other species of grass sure to be 
common in the same field.) 

The same great fundamental principle of protective coloration, which is the 
essential root of the matter in the case of the vertebrate orders we have been 
considering, namely the principle of oUiterative shading, holds, to a very large 
extent, among lepidopterous larvae. But here again we must sharply draw 
the line between mimicry and oUiterative coloration, because the former, which 
has played so small a part in the orders we have already considered, is among 
caterpillars both common and highly developed, almost outweighing in im- 
portance the other principle, with which it is in many cases intricately com- 
bined and interwoven. Mimicry, then, does not attempt to render a creature 
invisible as an actual, well-defined object, but causes him to appear, either 
wholly or in part, to be something else than what he really-is. The resem- 
blance of edible or harmless to inedible or noxious creatures for defensive, and 
to some degree the reverse for offensive purposes, constitutes one of the sim- 
plest and most generally recognized forms of mimicry, and one to which 
naturalists have given much attention. Another sort, more to our present 
purpose, consists in the resemblance of the unobliterated forms of single crea- 
tures to single well-defined details of their natural environment. This last 
principle is sometimes, notably in the case of certain caterpillars, altered and 
elaborated into what may be called compound mimicry. This consists in the 
imitation, by the surface-aspect of a single creature or part of a creature, 0/ 
more than one absolute detail of the environment, — which details, owing to their 
lack of an underlying obliterative shading, still appear to occupy exactly the 
position of the actual creature. The principles of obliterative coloration, on 

184 



the other hand, work together to render the creature's actual surface unrecog- 
nizable as the surface of any object or objects of the immediate foreground, 
causing it to pass for an empty space through which the background is seen. 

Not being entomologists, we know little or nothing about these larvae from 
the standpoint of nomenclature and scientific classification. We have taken 
them as we found them, valued them according to our recognition of their 
various devices of protective coloration, and classified them, for our own par- 
ticular purpose, according to these devices. In most cases we do not know 
more than one stage of a caterpillar, and it is possible or even probable that 
younger (or older) stages of almost any one of our most interesting specimens 
may be totally different. Our point has been merely to recognize wonderful 
cases of protective coloration, and to take them as they stand, for what they 
are worth. 

Beginning with the large green larvae, such as those of the Luna and Poly- 
phemus moths, which are disguised purely and simply by counter shading 
and background-color, aided by a slightly 'mimetic' system of leaf -vein 
markings and leaf-edge contour, we will trace the gradation of types to the 
caterpillars whose astoundingly effective disguises are purely mimetic. Such 
for instance are the larger gray, green, and brown twig-mimicking Geometrce. 
These larvae, being furnished with bodies whose general shape, color, minute 
surface-formation, and markings are copied perfectly from the twigs among 
which they feed, — some of them with forked heads which are exact fac- 
similes of the buds at the tips of many of these twigs, and others with heads 
which simulate the truncated ends of dead twigs, — complete the deception by 
clinging to a stem or branch by the back pair of legs alone, and standing out stiff 
and straight, absolutely motionless for minutes at a time. But true mimicry 
in almost all its forms has already been largely and appreciatively studied and 
described by several naturalists, and we shall therefore devote little more space 
to it than is necessary to establish clearly in the reader's mind its relation 
to the other systems of protective coloration among caterpillars. 

Class I. Simple obliterative shading and leaf-color, usually aided by leaf- 

185 



vein markings and leaf-like contour. This class includes most of the very large 
green caterpillars, such as those of the Cecropia, Polyphemus, Luna and 
Promethea moths, many of the Sphinxes, and, with modifications, the larva of 
Basilona imperialis, etc. Most caterpillars protected by this counter shading 
hang upside down, and are therefore, of course, dark on the helly and light on 
the back, exactly the reverse of creatures which stand back-uppermost. (A few 
larvae — some SphingidcB among the number — rest on the upper sides of twigs, 
and are counter shaded accordingly, from dark on the back to light on the 
belly, exactly like birds and beasts.) 

Plate XII, Fig. A, shows a Luna caterpillar in a natural position, a good 
example of the full working of fully developed counter shading. By this 
device the larva, hanging in proper position among leaves, is enabled to lack all 
appearance of solidity, and to ' melt ' perfectly into the general, indeterminate 
green of the mass of foliage which surrounds it. In addition to this purely 
obliterative device, the caterpillar is furnished with leaf-vein-like bands and 
a leaf -edge-like back-contour, so that if the eye of an enemy happens to detect 
its surface as that of a distinct object separate from the general green, the larva 
may still, by virtue of its perfect flatness of tone, greatly aided by these leaf-like 
markings, merely pass for a flat leaf, or part of such a leaf. Without these 
markings to further the deception, and to distract the observer's attention from 
the larva's surface-texture, this, closely though it resembles that of leaves, would 
often betray the creature, by its slight peculiarities of appearance. These 
markings bring in an element of mimicry, inasmuch as they help the larva, 
when he is revealed as a definite object, to pass for a leaf or leaf-portion no more 
distant than he actually is from the observer, rather than picturing the back- 
ground upon him. This is proved by the back-contour, which seems to mimic 
the wavy edge of a single, foreground leaf, with its serrations of full size, rather 
than reduced by distance ; and the vein markings also are in keeping with this 
plan, being pronounced and large. Many, in fact nearly all, of our large green 
caterpillars have this form of protective coloration, and the Luna is chosen 
merely as one good type of the class. There are many fine examples of it 

i86 



among Sphinx larvae, which often have the leaf-vein markings exaggeratedly 
developed. The Polyphemus caterpillar, which closely resembles the Luna, 
largely lacks these markings, but has an even more leaf-like contour.* There 
are few creatures in all nature better obliterated by shade-, color-, and pattern- 
devices than are many of these large green caterpillars, which are doubtless 
much sought after by certain birds, as for instance the Broad-winged Hawk 
{Buteo platypterus). A human eye needs much training to be able often to 
detect a Luna or Polyphemus caterpillar hanging amidst foliage. Fig. B shows 
the same Luna caterpillar with the back uppermost, the reverse of the normal 
position. It will be evident to any eyes that the creature thus placed, so that 
the proper effect of its light-and-shade gradation is exactly and doubly thwarted, 
is extremely conspicuous, and that neither its leaf-green color, nor its leaf-like 
markings and contour, both so extremely useful when cooperating with the 
proper effect of the fundamental light-and-shade-effacing. principle, can now 
avail it. The creature is now staringly revealed as a fat green larva, light on 
the back and dark with shadow below, — as even monochrome solid objects are 
plainly revealed to the eye. Figs. C and D are two Sphinx-caterpiUar pic- 
tures exactly corresponding to those of the Luna, as will be seen. Fig. C 
shows the larva in situ, Fig. D reversed. An interesting modification of this 
scheme is found in the caterpillar of Basilona imperialis, the Imperial Walnut 
Moth. Lacking distinct leaf-markings, it is furnished with scattered, long, 
light-colored hairs, which, when it is seen from a slight distance, completely 
blur its surface, and greatly help its rough but adequately 'obliterated' green 
body to blend with the general green of its foliage-background.f 

* The red warts, with a pearly luster, of which we have made no mention, and which are com- 
mon to both species, are larger and brighter in the Polyphemus. Whatever may be their other uses 
they lessen the larva's visibility, inasmuch as the tiny spots of gleaming light upon their tips suggest 
to the eye the glinting of light through holes in the leaves. The huge and gorgeous warts of the 
Cecropia caterpillar are not lustrous, and cannot serve this purpose, but they closely resemble dis- 
ease-excrescences upon leaves, and may well be strictly disguising devices. Or they may be also 
fixed defensive weapons, serving to make the larva unpalatable, as the branching bristles of the 
Automeris io caterpillar certainly serve to make it dangerous, to a would-be devourer. 

t With us these caterpillars feed chiefly on red maple and white pine, and those of the bluish 

187 



Class II. Counter-shaded Leaf-edge Caterpillars. The members of this 
class are protected by an exquisitely delicate cooperation of ohliterative shad- 
ing with minutely accurate flat-surface mimicry, and this system is variously 
modified in different branches of the class. But this new principle must be 
more exactly defined. By cooperation of mimicry with ohliterative shading, 
we mean a resultant mimetic resemblance achieved throughout on a basis of 
counter shading. Whereas pure mimicry is a matter of the actual form and 
surface-coloration of animals, irrespective of any artifice of light-and-shade, 
the mimetic resemblance to a flat leaf-edge in the case of these larvae is achieved 
by the aid of a delicate system of counter shading. That is, the elaborate single- 
leaf pattern worn by them looks perfect only when they are so lighted as to bring 
their whole counter-shaded body to an appearance of perfect flatness; or in 
other words, their superadded pattern as well as their general surface-color is 
obliteratively shaded to counteract the effects of the normal high-light and 
shadow. The markings are lighter, brighter, and sharper in proportion as 
they are situated on parts of the creature which are normally more averted 
from the light, and vice versa. (The oak-leaf larva shown in Fig. N is a good 
example of pure and simple leaf mimicry, as opposed to leaf mimicry dependent 
on counter shading) This composite scheme might seem to belong rather to 
ohliterative coloration than to mimicry, but we must call it a form of mimicry, 
for the reason that the resultant resemblance is to part of a definite object 

green pine foliage are almost always of a much more bluish green than those which feed on 
maple. 

Another interesting example of pigmentation perhaps directly affected by diet is that of the 
change from green to red undergone by many of the large caterpillars in the autumn, shortly before 
their transformation into chrysalids, and at precisely the season when many of their food-leaves are 
turning red. Not only the spinning-caterpillars, such as the Luna and Polyphemus, but also certain 
of the silkless ones, notably the Basilona imperialis just mentioned, often turn tawny, reddish, or 
almost bright red, or become strongly tinged with such colors, shortly before they stop feeding, in the 
late summer or autumn, when they have attained their full size. Thus it cannot be merely a matter 
of silk-development in their bodies; and it is further noteworthy that the specimens of B. imperialis 
which develop on pine or spruce trees (spruce is occasionally eaten) rarely or never turn wholly red, 
while their neighbors of the maple trees are often of a rich copper color, or even brighter, when they 
descend the trunks to enter the earth. 



EXPLANATION OF PLATE XIII 



Fig. E. larger-spotted 
BEECH-LEAF-EDGE CATERPIL- 
LAR IN POSITION, passing for a part 
of the leaf on which it is feeding. 



FiG.iF. SMALLER-SPOTTED 
BEECH-LEAF-EDGE CATERPIL- 
LAR IN POSITION. Of. Fig. E. 




G. LARiGER-SPOTTED 
B E E C IJrL^^E-ISipGE ..CATPIRPIL- 
LAR, DETACHED, INVERTED. '' , 



Fig. H. SMALLER-SPOTTED 
BEECH-LEAF-EDGE CATERPIL- 
LAR, DETACHED, INVERTED, 



M"^- 



i{t 



■;;*■?' 



Fig. I. WHITE-BIRCH-LEAF- 
EDGE CATEI^LLAR IN POSI- 
TlOSf, passing for a continuation of 
the leaf on which it is feeding. 



Fig. J. WHITE-BIRCH-LEAF- 
EDGE CATERPILLAR,DETACHED, 
BACK- VIEW. Cf. Figs. E— H. 



FiG. K. JAGGED-LEAF-EDGE 
(ELM?) CATERPILLAR IN POSI- 
TION. 



Fig. L. JAGGED-LEAF-EDGE 
CATERPILLAR INVERTED. (The 
direct sky-light making leaves and 
caterpillar bluer. ) 



'V*,' ; 

Figs. E, F, G, H, and K, pointed from life by, Gerald H. Thayer; Figs. 1 and J by A. H. Thayer (Leaves, E.'B. T ); 

Fig. L. by Louis A. Fuertes 




AJ10EN ScCO B(M.TIMOHE . 



in the actual position of the counter-shaded creature, rather than to its back- 
ground. With this explanation we can proceed to a more particular de- 
scription of these wonderful larvae. They feed, and, unlike most caterpillars, 
rest, on the edges of leaves, and as their weight always draws downward the 
edge to which they are clinging, they are to some degree caterpillars of the up- 
side-down habit, and accordingly must have, in order that their appearance of 
solidity shall be effaced, an inverted obliterative gradation of light-and-shade. 
Unlike the larger counter-shaded caterpillars, such as the Luna, which cling to 
stems far in among the foliage, they are usually fully exposed to view, on the 
edges of outside leaves, and hence it is imperative that their surface, perfectly 
flattened in appearance, should imitate as closely as possible the leaf-texture. 
The degree to which this is achieved is one of the most exquisite and wonder- 
ful things in the whole field of protective coloration. No caterpillar is harder 
to detect, at the closest range, than is one of these beautiful leaf-edge larvae in 
its natural position. The minute reticulate markings of the healthy leaf- 
surface are closely copied on the larva's counter-shaded body by small dark 
flecks, and, in addition, he often wears facsimile pictures (rendered perfect 
by the same process of counter shading) of leaf-disease-spots. These spots, 
and even the general coloring, vary somewhat in size and shape, but always 
within limits beyond which the disguise would begin to be impaired. We 
have seen many such caterpillars, representing several species and probably 
several mere varieties. As a rule, it seems to be true that one kind of tree 
harbors only one kind of 'leaf-edge' larva, which is almost or quite peculiar to 
it, and rarely to be found on any otherplant. In the case of the beech, however, 
which feeds a greater variety of particularly interesting ' disguised ' larvae than 
any other tree we know, we have found three quite distinct species of the leaf-edge 
class infesting it, and one of them, whose coloration is less distinctive than that 
of most, is pretty often found on other trees. Again, the form inhabiting 
certain kinds of maple, and wearing the deep-red spots of diseased maple trees, 
occurs also on witch-hazel, and its spots are then usually browner and smaller.* 

* Possibly we are here speaking of two species. 
189 



Plate XIII, Fig. E, shows the larger-spotted species of beech leaf -edge larva, 
in its normal position. Fig. F shows the smaller-spotted species in position. 
Figs. G and H show these two larvae inverted, against a black background. 
Figs. I and J are two sketches of a white-birch leaf-edge larva, I being the 
creature in situ, and J a simple back view. Of this larva we have seen only 
two specimens. It is but sUghtly shaded from dark to light, and either lives 
usually very far in among the leaves, where the light is diffuse, or else, because 
it feeds on rather stiff leaves, whose edges are but slightly pulled downward 
by its weight, can make little use of counter shading. The light spots on this 
caterpillar closely picture the small, transparent worm-scars so common on 
the leaves of the white birch. 

As we have said, the principles involved in the protective coloration of 
this group of caterpillars are variously modified. The forms just described 
are among the commonest and most noteworthy of those we have seen, but they 
lack one element of finish which is found in caterpillars of another branch of 
the class. Those already described have backs very slightly indented be- 
tween the segments, and without humps, hence their contour can never pass 
for the perfect edge of a leaf which is in any degree serrated, as most leaves are. 
But as they freely mow away whole sides of leaves, and usually rest close to the 
stem on the mutilated edge, this is hardly a lack. They merely pass for a con- 
tinuation of a gnawed and imperfect leaf-edge, in whatever position they cling, 
except in cases where they are so far from the stem that their backs are 
farther out than even the unbroken leaf-edge could be — as sometimes when 
they are beginning a new leaf. In such a case the smooth back-line is, momen- 
tarily, a defect. (This need hardly be taken into account, however, because 
it is the habit of these larvae to work in along the midrib of a leaf, from a 
position on the stem, and it is only in rare cases that their backs are out beyond 
the line of a normal leaf-edge.) The caterpillars of the other type, of which 
we have as yet seen only one individual, may be called the contour leaf-edge 
larvae, for their back-contour is formed in close imitation of the perfect, serrated 
edges of the leaves on which they feed. This resemblance is effected by a 

190 



series of high, double-pointed humps, one on each segment back of the front 
feet, and is further aided by certain markings between and on these humps. 
Such a caterpillar, therefore, doubtless tends to keep itself adjusted so that 
the line of its back continues that of the unbroken leaf -edge, from each side of 
the hole it has gnawed, and in which it is resting. It is also furnished with 
diagonal darkish lines, one on each segment, which closely resemble the parallel 
vein-markings on such leaves as elm and birch. Our specimen had no disease- 
spot representations. The gradation from dark to light (dark on the belly 
and light on the back, of course, because this is one of the upside-down cater- 
pillars) is perfect, and the larva's invisibility of course depends primarily 
on this, as the two figures (K and L) show. Unfortunately, our only specimen 
was found on the ground, and we cannot be sure what its particular food 
plant is. The fact that elms were common close about it, as well as its beau- 
tiful resemblance to the edge of the small elm leaf on which we placed it, 
make it seem likely that it belongs on this tree. This caterpillar may be said 
to constitute a separate division of the counter-shaded leaf-edge class, which 
division we may define as follows: 

Class II, Division A. Involves all the principles assigned to Class II 
(with the exception, as far as we know, of the leaf -disease-spot picturing), with 
the additional element of leaf-contour mimicry achieved by humped segments, 
and pronounced leaf-vein markings. (Fig. K shows the caterpillar in posi- 
tion, Fig. L inverted.) 

Class II, Division B. The protective coloration of these larvae involves 
the principles already assigned to Class II, cooperating with an additional 
distinct element of background-picturing. We have here a new and very 
wonderful departure from the simple leaf-edge tj^es already described. The 
caterpillar shown in Plate XIV, Fig. M, a strict leaf-edge inhabitant, is, down 
to a certain point on its back, exquisitely counter shaded and colored to re- 
semble the bluish-green upper surface of a beech leaf, its usual food. Its 
body is even furnished with minute black specks, in apparent imitation of the 
faintly marbled aspect of the leaf. But this graded green, fading into a pure- 

191 



white line along the sides of the back, terminates then abruptly against the 
smooth, deep yellow green of the back itself. Thus it appears that the 
perfect flat-leaf-edge color achieved by counter shading extends over part of 
the larva, and then suddenly gives place to an entirely contradictory and at 
first inexplicable stripe of dark, exactly where the culmination of paleness would 
normally occur. Finding the larva on the ground, one may well be puzzled, 
but the first sight of it normally situated on a leaf is a revelation, as our picture 
(Fig. M, i) shows. The counter-shaded blue-green belly and sides repre- 
sent an extension of the upper side of the leaf, the white line is an intensified 
representation of the line of the leaf-edge, and the sharply contrasted and 
deeply shadowed yellow-green back simulates perfectly the shadowed under- 
side of a leaf, either the same one or one slightly more distant. If we examine 
the caterpillar very closely, we discover still another wonderful detail of its 
disguise. The dark-green back itself is slightly counter shaded to escape all 
trace of a solid appearance, and to match perfectly the monochrome under surface 
of leaves. A narrow yellow line runs along the middle of the back, and this 
serves to efface the culmination of shadow which would otherwise appear 
there. In the case of this leaf -edge larva the green back doubtless often passes 
for the underside of the same leaf, as shown in the picture (Fig. M, i), 
but in that of certain larger caterpillars which wear a similar device, as for 
instance the larva of the common smaller hog-nosed woodbine caterpillar, the 
illusion is less exact; and as this caterpillar rests on a stem rather than a leaf- 
edge, even its light patch often passes for a portion of some partially concealed 
leaf, rather than for the continuation of a wholly exposed one. 

The modifications and different adaptations of these various principles 
are almost unlimited, and we can only hope to give examples of a very few 
most highly representative and easily comprehensible forms. Fig. M gives 
three representations of the beech larva just described, i being the larva in 
position on the leaf-edge, 2 the same detached from the leaf, and 3 a simple 
back-view of the creature. These caterpillars are usually unspotted, as here 
shown, but are sometimes marked with brown patches closely resembling 

192 



E.Vl'IANATION OK PJ.ATK XIV 



Fig. M. unspotted B10F,C:H-LKAF-EDGK CATlCHl'ILLAll 

1 . In position, part of him passing for a continuation of the leaf on 
which he is feeding, and part of him for the underside of the s-anie leaf. 

2. Larva delaiBhed from the leaf. 
:). Ditto, back-view. 



Fig. N. oak-leaf-edge CATERPILLAR 
Detached. 



Fi.iP. O and P. OAK-LEAF-EDGE CATERPILLAR 
Tn position. 

Fitt. Q. ORUMPLED-AND-VVITHERED-LEAF-EDGE-MIMICKING CATERPILLAR 
In position, representing edge of diseased portion of leaf. 



..v'^iKj'.- "■'■ 



Painted fronf) life by Gerald H. Thayer (Leaves, Figs. M. and Q., E. B. T.) 



y 




•JBcCCI BAUriMDBE. 



those common on beech leaves — much like the species shown in Fig. G. We 
have also seen one or two wearing almost the same general scheme of pattern, 
but done as to color wholly in brown, — and it happened that these were found 
resting on twigs or stems, instead of leaf-edges. 

Class III. Purely mimetic leaf-edge larvae. Complete leaf-edge mimicry 
without obliterative shading. The caterpillar shown in Figs. N, O, and P, 
although strictly a leaf-edge larva, deviates so widely from one of the main 
principles of that class as above defined that it must be treated separately. It 
lacks, namely, all trace of obliterative shading, and its beautiful, shiny, oak- 
leaf green, more closely like a leaf in surface-texture than is that of any of its 
relatives we know, is of one uniform shade and tint, so that the larva can never 
escape the full appearance of a solid, cylindrical body. But the perfect leaf- 
color and texture of its green parts, in cooperation with the marvelously minute 
counterfeit of the transparent, brownish worm-scars so common on oak leaves, 
which the remainder of its body wears, make it — ^when, as is its wont, it hangs 
inverted from a leaf — ^pass for the down-curled edge of it. The vein-pattern 
is minutely copied on the larva's brown ^arts, and between the green 
and the brown there is usually a narrow, irregular yellow line, exactly such as 
the leaf commonly has. The broken-leaf-edge aspect is further aided by the 
brown hump on the caterpillar's fourth segment. Altogether, though lacking 
light-and-shade gradation, this is one of the most wonderful of protectively 
colored caterpillars, and one of the very hardest to detect in situ. We have 
sometimes found this caterpillar on beech, the leaves of which have worm- 
scars very like those of oaks. 

Class III, Division A. (Fig. Q.) Structural and pattern mimicry of an 
irregularly crumpled leaf-edge (thus approaching the scheme of the structur- 
ally mimetic larva shown in Fig. S, though the latter is not a leaf-edge inhabi- 
tant). This division includes un-counter-shaded leaf -edge caterpillars of a 
different type from the oak larva — those, namely, which, by color, pattern, 
and curiously humped backs, simulate the irregularly crumpled and withered 
edge of a leaf. Their bodies are almost always crossed near the head by a 

193 



band of leaf-green, which greatly furthers the deception. There are many 
wonderful caterpillars of this type, usually a good deal larger than the one 
here shown, which is the only one we have succeeded in painting. 

Class IV. Partial mimicry of a detail oj the normal surroundings, with a 
polished hack which under certain conditions rejiects the color of surrounding 
objects, combined with flat-leaf-edge counterfeiting, achieved by light-and-shade 
gradation. The pretty caterpillar shown in Plate XV, Fig. R (No. i reflecting 
nothing, No. 2 reflecting green, and No. 3 reflecting red), is our sole example 
of this class. Its light, extremely shiny back, which serves for shadow-efface- 
ment when the caterpillar hangs upside down, serves also for actual reflection 
of the color of the encompassing foliage (as in the white spider shown in Plate 
XVI, Figs. V-Y), while the yellow stripe down its side must usually pass for 
the stem of some other poplar leaf than the one on which it is feeding. The 
fact that this well-pictured stem must, owing to its large size, appear to be at 
least as near the observer as the caterpillar actually is, allies the case to partial 
mimicry rather than to simple obliterative coloration. When the caterpillar 
rests on a yellow stem, rather than a leaf-edge, as it often does, the mimetic 
element is still more pronounced, for then the stem which he is in fact conceal- 
ing with his feet is by his yellow stripe made to appear to pass on uninter- 
ruptedly, if somewhat crookedly, and the remainder of his body merely merges 
with the general green which surrounds him. This larva we have found only 
on small-leaved poplar trees. 

Class V. Complete structural mimicry of a common detail of the creature's 
habitual inanimate surroundings. The wonderful little caterpillar which we 
have chosen to typify this class bears on its back a double row of large fernlike 
fronds, with perfectly developed stem and branches, and when feeding or 
resting amidst the curled-up edges of unhealthy maple or other leaves, which 
it -evidently mimics, is almost impossible to detect. In its elaborateness and 
efficiency, this disguise is among the very most wonderful. At the season 
when the caterpillar is to be found, most of the forest trees have many of these 
partially withered leaves. Wherever the creature stands on a leaf, it passes 

194 



EXPLANATION OF I'l.ATB XV 



Fig. R. 'MIRROR-BACK' CATERPILLAR 

Painted from life by Gerald H. Thayer, 

1. Reflecting nothing (save the sky-light). 

2. Reflecting leaf-green. 
I). Reflecting a red leaf. 



Fig. S. 
CRUMPLED-LEAF CATERPILLAR 

Painted from life by G. H. Thayer. 
(Leaf, Emn^a B, Thayer.) 

1. In position, back-view. 

2. Ditto, side-view. ' '?; 

3. Detached, enlarged. 



Fig. T. * 
CURLED - DEAD r LEAF - MBIICK- 
ING SPHINX CATERPILLAR, IN 
POSITION. 



Painted from life (larva and withered leaf) ..bvtfouis 
A. Fuertea. (Live 'fpavies, G. H. T.) -'W^ 



;:t^. 




SfCO. DALTrMOHF _ 



for a dead and crumpled spot. The specimen here shown had lost one of the 
fronds from its right side. (These caterpillars are said to shed their fronds 
and weave them into their cocoons.) (Fig. S, Nos. i, 2 and 3.) 

Class VI. Highly developed color-and- pattern mimicry, scarcely aided by 
modifications of form, of a detail of the caterpillar's usual inanimate surround- 
ings (Fig. T.). The plants on which this late-developing sphinx larva 
commonly feeds, bear, almost invariably, at that season, a few black dead 
leaves, frost-bitten or otherwise wilted — and the caterpillar, hanging head 
downward, is a close counterfeit of one of these. The imitation is very close 
indeed, — even the usual dark hole at the bottom of such a leaf being rendered 
by the black spot on the caterpillar's head, intensified by the encircling white,* 
and the vein-markings being accurately copied by diagonal stripes and fine 
reticulations. The tail-horn, which this larva has in common with most 
sphinx caterpillars, here serves to counterfeit a leaf-stem, the midrib continu- 
ation of which through the leaf is closely imitated on the caterpillar by a pro- 
nounced light line. These markings and details of form are largely the same 
as those found on ohliteratively shaded sphinx larvae, where they serve the 
same general purpose of leaf-stem and vein imitation; but the present 
case, being one of pure and simple mimicry, allows of a clearer and more 
definite development of these details. Notice this caterpillar's complete 
lack of light-and-shade gradation. He is equipped, not to be unapparent 
as a solid object, and to merge with the details of his average background, 
but to appear to be another kind of definite, rotund body than such as he 
really is. 

Class VII. Compound mimicry of normal inanimate surroundings, coupled 
with an 'element of background-picturing. (Plate XVI, Fig. U.) This cater- 
pillar's several light-colored longitudinal stripes resolve themselves into the 
appearance of separate needles of the white pine tuft in which it feeds. But 
the darker and broader green stripes (sometimes partly dark red) then pass 
for the general background of needles, against which the light stripes show as 

* See Chapter XX, p. 125; Chapter XXII, p. 157, and Fig. 120. 



separate, glistening, nearer ones. Thus the scheme departs from true mimicry 
and approaches obliterative coloration, as it has already departed from simple 
mimicry by the fact of its simulating more than one absolute foreground object. 
This is one of the uncommon and noteworthy cases where an element of oblitera- 
tive coloration is present without obliterative shading. The caterpillar's head 
is marked with red and yellow, in close imitation of the scales at the bases of 
the needles — and it usually rests with its head against or near these scales. 
It is a kind of sphinx, and, as far as we know, it feeds exclusively 
on pine. Indeed, its mimetic resemblance to pine needles has been com- 
mented on by entomologists. In the picture. No. i is a back view. No. 2 a' 
side view. ^ 

We have now, in the matter of caterpillars, reached the end of our material. 
The forms mentioned and figured are, as has been said, only a very few out of 
an enormous number. We ourselves have found many other equally note- 
worthy ones, which for various reasons we have failed to figure. Among the 
most interesting of those omitted is the caterpillar of one of the Lappet moths, 
which achieves in a remarkable way very simple mimicry of a slight protub- 
erance on a thick tree branch (the sort of perch on which it, unlike most cater- 
pillars, is wont to rest)^ Its body is much flattened, and fits closely to the 
branch; and it is marked, irrespective of the scattered hairs, in close imitation 
of the bark. There is no light-and-shade gradation, and the shadowed sides 
of the caterpillar, as well as the shadowed crevice which would show between 
it and the bark, are beautifully bridged over by an obliquely descending fringe 
of numerous hairs. So slight is the larva's actual surface-rotundity, indeed, 
that under favorable conditions it doubtless seems to merge with the flat or 
slightly rounded bark-surface; so that this is another caterpillar whose disguise 
in part achieves 'obliteration' without counter shading. 

We have at least figured and described enough widely diverse caterpillar 
disguises to suggest the wonderful richness of this great field of study, still 
almost unexplored. Anyone who will devote a few late summer and early 
autumn days to caterpillar hunting, along wooded roadsides — ^finding them by 

196 



EXPLANATION OF PLATE XVI 



Fig. U. pine-tuft CATERPILLAR 

Painted from life by Geraid H. Thayer, 

1. Back-view. 
3. Side-view. 



Pigs. V, W, X, Y, PORCELAIN-WHITE SPIDER 

Painted from life by Gerald H.Thayer. (Leaves, E. B. T.) 

Figs. X and Y, spider suffused with green light amid foliage. 



PLATE XVI 




the aid of their droppings on the ground, and trying always to see them in their 
natural positions — ^will not only soon be acquainted with many forms like 
those we have described, but will, if he has the trained artistic sight with 
which to recognize them, discover many new and equally wonderful 
cases. 



197 



CHAPTER XXVI 

A GLANCE AT INSECTS OTHER THAN LEPIDOPTERA (ORTHOPTERA, COLEOPTERA, 
HYMENOPTERA, DIPTERA, ETC.), AND AT SPIDERS 

HERE we should be totally overwhelmed by the hugeness of the subject, 
and foiled by our own ignorance, if we sought to give more than the 
slightest general sketch of the main prevailing principles. Passing by * the 
wonderful purely mimetic developments, such as those occurring among 
insects of the families Mantidce and Phasmidce (walking sticks, leaf insects, 
mantises that mimic flowers, etc.), which have been studied and described by 
many naturalists, and with many of which the world at large has long been 
familiar, we will confine ourselves to a rapid survey of the mass of less 
obviously remarkable types. Beginning with the three main families of 
Orthoptera (grasshoppers, locusts, and crickets) we find obliterative shading 
playing its usual important part, though in less uniformly high development 
than among vertebrates. Ground-perching locusts {Acrydiida) are all (?) 
obliteratively shaded, in full, and furnished with ground-picturing patterns, 
some of which are almost as minutely finished as those of Nighthawks, desert 
snakes, etc. Some kinds habitually perch on rocks, and have true and fine 
rock-patterns, much like the Nighthawk's. Others, again, resorting much 
to sand, and bare, dry earth, have more sandy-peppered patterns, like that 
of the Puff Adder. Somewhat more brightly colored, as a rule, are the 
many species which habitually perch on or amidst terrestrial vegetation. They 
are flecked and patched, banded and striped, with grass- and ground-weed 
tints — green, yellowish, red, olive, brown, and black, in more or less general- 
ized picture- patterns (or sometimes more crudely 'ruptive' ones). Lo- 
* As we ignore, for the present, all questions of ' live '-mimicry among these insects. 

198 



custs, as a rule, "lie close," sitting tightly folded; thetr fore-wings (which, with 
the head, sides, and legs, bear the counter shading and fine patterns) wholly 
hiding the broad, membraneoug hind-wings. These are often brightly and 
boldly colored, without minute patterns, and when expanded in flight, against 
sun-variegated backgrounds, they lessen the conspicuousness of the moving 
insect just as do the bold 'ruptive' markings of many butterflies (and moths). 
(See Chapter XXVII.) Some of them, again, must under certain conditions 
act as 'dazzling '-marks, by their sudden display and equally abrupt eclipse. 

Among the Locustida or true grasshoppers, some of the more terrestrial 
kinds have much the same general system of protective coloration as have 
the herbage-haunting Acrydiida above described. For the most part, how- 
ever, even these terrestrial ones are less finely patterned, having mere simple 
'ruptive' patches of green and brown, or kindred colors, and the bright-back- 
ground picturing above mentioned plays but a small part with them. Many 
of the more arboreal kinds — of which the well-known "Katydid" {Platy- 
phyllum concavum) of the eastern United States is a good example, and even 
some of those that haunt terrestrial herbage, are disguised by leaf mimicry, 
for the attainment of which the whole body seems to have been modified. 
The pith of the resemblance, however, lies in the fore-wings, which, when 
folded, largely or wholly (according to the species) inclose and hide the body, 
and which, being of a perfect, bright leaf-green, are also marked with a leaf- 
like midrib and netted side-veins, so that, in profile, the insect closely simu- 
lates a narrow leaf, or portion of a leaf. But, as in the case of the leaf -edge 
caterpillars described in the preceding chapter, this mimetic resemblance 
is largdy indebted to obliterative shading. ExternaUy convex, and folded 
downward over a more or less cylindrical body, these fore-wings are made 
to look flai by a delicate counter shading, just as we have seen in the case of 
the caterpillars' bodies. When, as is the way with several species of leaf- 
mimicking grasshoppers, the fore-wings are comparatively narrow, so that 
much of the body is exposed, it is obliteratively shaded, to the full, and hence, 
in the right position relative to the light, it too is 'flattened,' and continues 

199 



the flat-leaf aspect of the wings. But the effect in this case is less strongly- 
mimetic, for the body presents a less leaf-like surface than the wings, especially 
in its lack of venation. Indeed, some of the green grasshoppers have scarcely 
more than a general obliterative equipment of counter shading and foliage- 
color. 

The next family of Orthoptera, the Grillida or crickets, have less to show 
in the way of disguising-costumes. Mainly nocturnal, and in many cases 
subterranean and fossorial, they largely lack highly developed colors and 
patterns. Most of them are black, blackish, or brown, — ^monochrome, without 
pronounced obliterative shading. Diurnal kinds, which stay above ground, 
wiU doubtless all prove to be obliteratively shaded, though still dull-tinted, 
—very few (or perhaps none) of them sharing the livelier coloration common 
among their relatives the locusts and grasshoppers. 

The cockroaches and earwigs {Blattida and ForficulidcB) are likewise 
nocturnal — shy and seclusive haunters of dark holes — and their protective 
coloration amounts, apparently, to little or nothing beyond a general dull, 
earthy brownness of tint. 

The Coleoptem, or beetles, in the adult state,* are, for the most part, tough, 
hard, and shelly, and probably less welcome food, to the majority of insect- 
eating animals, than are caterpillars, locusts and grasshoppers. Many of 
them, moreover, are equipped with rank defensive (?) stenches, as well as with 
strong biting jaws; and many are nocturnal — skulking by day under stones, 
under rotten bark, or in other safe retreats. Considering beforehand all these 
facts, we should not expect to find beetles, as a class, particularly well pro- 
vided with disguising-costumes ; and they certainly are less so than some of the 
more ' succulent ' tribes of insect. On the other hand, they are by no means im- 
mune from enemies, nor do they, in the great majority of cases, lack oblitera- 
tive coloration. Few have simple obliterative shading, as few have the regular 
perching-habits, the habitual ' same-side-up-ness,' indispensable to the full 

* Their larvas almost all live hidden away from the daylight, and are as a rule monochrome 
and patternless, — often colorless. 

200 



operation of that disguise, but many are equipped with brilliant iridescent 
or metallic colors — green, blue, purple, bronze-red, bronze-yellow, etc. — 
which strongly tend to obliterate them amid and against vegetation. The 
fact that some nocturnal and subterranean kinds as well have rather brilliant 
metallic colors * merely reminds us how much is still to be learned about their 
habits. But it is, as far as I know, among truly diurnal species that the highest 
brilliancy of coloration occurs. Sometimes, as on certain tiger beetles {Cicinde- 
lida), etc., brilliant iridescence is combined with small, dull, sheenless spots, 
and the effect of this combination, in a proper view, is highly obliterative, 
particularly if the beetle is also counter shaded. Or again, iridescent brilliance, 
in spots or stripes, may be a small factor of a soberer pattern. Innumerable, 
indeed, are the variations of generalized obliterative pattern — 'secant,' 'rup- 
tive,' etc., in bands, stripes, spots and mottlings — ^which occur among beetles. 
Black, yellow-buff, reddish brown, and yellowish green are probably the 
commonest colors of the bolder patterns, which are strongly obliterative 
against most natural backgrounds, though by no means highly specialized. 
Transverse 'secant' marks predominate in these patterns, in accordance with 
the simple laws of 'obliteration,' already many times explained. But much 
more subtile patterns also occur on the Coleoptera, especially among those 
which habitually rest on the bark of trees in the daylight. Even on beetles, such 
finely mottled and grizzled tree-bark patterns are usually accompanied by oblit- 
erative shading, and hence are true 'picture-patterns.' If the counter shading 
were absent, the disguise would be mimetic, making the beetle look like an ex- 
crescence on the bark. But we do not know of any pronounced cases of this 
kind. Some flower beetles also have full and delicate obliterative shading. Of 
these the American Rose Chafer (Macrodactylus subpinosus) is a good example. 

But for all their frequent obliterative patterns and rich, iridescent vegeta- 
tion-colors, the Coleoptera, as a group, are far from taking top rank among 
'disguised' animals, or even among disguised insects. 

In the order Hemiptera there are relatively even fewer notable types of 

* Most of them, however, are black or blackish. 
20I 



disguise. Cicadas (Cicadadce) are among the largest and finest insects of 
this group, and their disguising-coloration, in the case of some kinds at least, 
is very elaborately wrought. The Common Dogday Cicada of eastern North 
America is the species with which we are most familiar, and it will suffice 
as an example of the family. The broad, plump body of this insect is 
obliteratively shaded, being grayish and pinkish white beneath, with some 
faint markings, and shading into deep blackish brown above — on the upper 
sides of the head, abdomen, and thorax. This brown upper side, moreover, 
bears a beautiful, bark-like picture-pattern, made by narrow bands of light 
olive-green upon the darker ground color. On the abdomen these bands are 
simple and transverse, on the thorax and head they are beautifully branched 
and netted. Though the Dogday Cicada has not strictly regular perching- 
habits, it is an eminently arboreal insect, and spends most of its time clinging 
to the bark of tree trunks and branches, in which situations both its counter 
shading and its mottled pattern often come fully into play. When, as is also 
frequently the case, it sits upon and among small twigs, either in trees or 
bushes, it is apt to have more varied backgrounds, and its rich but none too 
specially adapted obliterative pattern matches these nearly or quite as well as 
it does the single plane of near-bark surface. 

Some at least of the larger plant bugs — such as the stinking squash- 
and fruit-bugs of eastern North America — are counter shaded. Anasa 
tristis, for instance, the Common Squash-bug, is blackish above and yellow- 
ish below. It lacks pronounced markings, although several of its kindred 
have well-developed obliterative patterns, of various kinds. Probably, on 
the other hand, some of them bear mimetic resemblances to parts of their 
food plants. This is certainly the case among the Membracida, or Tree 
Hoppers. These little insects are for the most part sluggish and still, 
clinging close to the branches and twigs of trees, whose bark they perforate 
with their sharp piercers for the sake of drinking the sap, which is their sole 
nourishment in the adult state. When disturbed, they leap from their perch 
with surprising force, and fly to another resting-place. Dr. Harris ("Insects 

202 



Injurious to Vegetation," p. 222) says of one species, which inhabits the 
locust tree: "They never sit across the limbs, but always in the direction 
of their length, with the head or fore part of the body toward the extremity 
of the branches. On account of their peculiar form, which is that of a thick 
cone with a very oblique direction, their dark color [without obliterative shad- 
ing], and their fixed posture while perching, they would readily be mistaken 
for the thorns of the tree ..." Such mimicry of excrescences on twigs is 
probably common to many members of the Tree Hopper family. Some, 
however, have patterns which cannot well lend themselves to a simple mimetic 
resemblance, and whose effect must tend rather toward obliteration. The 
little Leaf Hoppers (TettigoniidcB, etc.) are often very bright-colored — green 
and red and yellow, in sharp, clear patterns — like tiny parrots. The effect 
of this motley coloration, against flower-, leaf-, and stem-surfaces, is of course 
obliterative — especially as the little hoppers are also counter shaded. Very 
likely, however, there are also definite mimetic developments among them. 
Plant lice or aphides {Aphidida) are of various tints, from dark brown and 
grayish black to fair, translucent green. As a rule, their color closely matches 
that of the plant surface on which they habitually feed and rest. Some of them 
are blotched or speckled, but few or none, I believe, have truly elaborate 
patterns. Nor do their costumes show more than a slight tendency toward 
obliterative shading, although the actual translucence of some kinds nearly com- 
pensates their lack of this device ( — ^both weakening or even obliterating the 
light-and-shade of their own bodies, and preventing their casting shadows 
on the leaf- or flower-surfaces on which they sit). Some, in their early life, 
are cloaked — and, likely enough, protected, though certainly they are not 
conceded — ^by a covering, sometimes enormously developed, of white, soft, 
cottony down. These white-tufted bark lice are a familiar sight on willow 
and alder bushes. 

Many other forms of hemipterous (and especially homopterous) insect 
might be mentioned, but mainly to show their general dinginess of coloring, 
which seems in keeping with their habits. Many of them are nocturnal and se- 

203 



elusive, like the cockroaches and earwigs, and have little or no special costume- 
development. Monochrome blackish, and unmarked, are also certain aquatic 
forms which live exposed to the daylight, such as some of the Water Boatmen 
(Notonecdidce). It is likely that, for one reason or another, such insects are 
little sought as prey by the higher animals. But many of the larger sub- 
aquatic bugs are mud-colored, and some of them are decidedly pale-bellied. 

Three important insect orders remain to be glanced at in this chapter, 
namely, the Hymenoptera (bees, wasps, borers, etc.), Diptera (flies, mos- 
quitoes, etc.), and Neuroptera (dragon-flies, ephemera, etc.). In these orders 
obliterative shading does not play a uniformly dominant part. The insects 
comprising them are for the most part winged, and not only winged but ac- 
tively aerial, and depend much on their powers of flight for escape from enemies. 
Some of them (dragon-flies, wasps, etc.) are themselves ferocious hunters, 
and too big and active to be eaten by the smaller insectivorous birds; while 
most of the flying Hymenoptera are terribly armed for offense and defense 
with poison-injecting stings, so that they are avoided by the general run of 
insectivores. Again, many of the Diptera and most of the Hymenoptera have 
no fixed perching postures relative to the prevailing light, but sit both above 
and under twigs and leaves, etc. This last fact alone is a sufiicient reason 
why these insects, as a class, cannot greatly profit by obliterative shading. 
Some of them have it, to be sure; and it does work, more or less, when they 
cling to the undersides of things, or sit on a surface perpendicular to the earth, 
— provided, in both cases, that the surface belongs to an opaque substance, 
and is of sufficient extent to cut off much light from the insect's 'underside.' 
But since they also cling beneath slender twigs and translucent leaves, the 
obliterative effect of their counter shading, when they have it, must often be 
wholly upset, and this alone, as we have said, is reason enough why many of 
these insects should be nearly or quite as dark below as above.* 

*In this book the term counter shading, when unqualified, means shading from dark above 
to light below. Insects like many Diptera that have their darkest details on their under side may profit 
by this in situations we do not understand. In general, it is not safe to deny to any coloration what- 
ever, concealing functions under circumstances not yet recognized. — A. H. T. 

204 



In spite of their toughness and their terrible weapons, the stinging Ry- 
mmoptera are preyed on by a good many birds; and though as a rule not 
counter shaded, they are furnished with bold obliterative patterns of many 
sorts. The predominant type, perhaps, is a system of sharp transverse bars 
of dark and light, by which the insect is 'cut up' as the zebra is by his bands. 
Yellow and black are the prevailing colors of these patterns— though white 
and buff often take the place of yellow, and fuscous, tawny brown, and olive 
(plant-shadow colors) the place of black. Such markings are fundamentally 
and very potendy obliterative against their wearers' average backgrounds 
of green vegetation in sunlight and shadow, and also amidst yellow flowers. 
Sometimes the pattern is simplified to a 'ruptive' one of two or three broad, 
unmarked patches of black and yellow, or black and orange — as on some 
of the bumblebees, — or still further simplified to a nearly monochrome cos- 
tume of mingled. plant- and shadow-like greenish yellow. Some wasps and 
bees, again, are uniformly almost black, and do not seem to have obliterative 
devices of any kind — except in the cases where the black is transfused with 
metallic color.* On the other hand, the transverse 'secant' pattern is often 
highly elaborated, consisting of many narrow, sharply defined, contrasting 
stripes, varied on the thorax and head by more broken and irregular mark- 
ings. Such is the case with certain wood wasps or hornets, e. g., the common 
"Yellow Jacket" {Vespa vulgaris). Among the "sawflies" and "borers" 
{SiricidcB, etc.), there is much variety in coloration as well as form. Glossy 
black, varied to steely blue, is perhaps the most characteristic color of these 
insects' bodies, but with it are often combined red, orange, yellow, brown, 
etc., in comparatively simple 'ruptive' and 'secant' obliterative patterns. 
Though lacking finer 'bark-pictures,' as well as counter shading, some of 
these borers, etc., are very inconspicuous when seated on the trunks of trees. 

The wings of most Hymenoptera — as those of most of the other aerial 
insects mentioned in this chapter — are transparent, and hence essentially 
inconspicuous at all times, except when they brightly 'shine' — ^as a glass 

* See footnote, p. 204. 
20s 



window may. Sometimes they are merely translucent, being clouded with 
color, — such color, usually, as continues the background-picturing of the 
head and thorax when the wings are folded. In some cases, again, the 
wings are barred or spotted, and these markings have of course an oblitera- 
tive tendency. 

Iridescence is fairly common among Hymenoptera, and there are some — 
chiefly small kinds — ^which are equipped with uniforms of intensely vivid 
changeable color, ranging sometimes from bronze-red to blue-green or green- 
blue — like the back of the jacamar* among birds, but still more brilliant. 
Green is the dominant color of almost all such costumes, which are in the 
highest degree obliterative amidst vegetation, as we have already seen. 

Some flies, too, have obliterative uniforms of iridescent green and blue, 
as everybody knows. They are, I believe, rarely or never as brilliant as the 
very finest of those worn by Hymenoptera, though often veiy rich and beauti- 
ful. The coloration of the Diptera in general difl[ers but little, in essentials, 
from that of the Hymenoptera. [The bolder patterns and colors of the 
Hymenoptera fit their more energetic lives, which bring them against bolder 
background differences.] f But as the dipterous insects are softer and more 
defenseless, so are their concealing equipments somewhat more elaborately 
developed. Many are counter shaded, and habitually perch on the tops of 
things. Some of the more aerial, flower- and foliage-haunting kinds, have 
bright, transversely 'secant' patterns of yellow and dark brown or black; but 
this coloration is less characteristic of them than of the Hymenoptera. The 
close likeness in color and pattern between certain stinging wasps or bees and 
stingless flies has led naturalists to suppose that the flies are mimics of the 
bees. This resemblance, however, is quite in keeping with the similarity in the 
insects' forms, habits, and environments, and less remarkable than many other 
kindred cases which cannot possibly be connected with mimicry. 

Flies are often dingily colored, and — especially those which have counter 
shading and more or less finely mottled patterns — ^fitted for "lying close" on 

* See p. 90, Chapter XVI. t Interpolation by A. H. T. 

206 



dingily colored surfaces. But many kinds are too promiscuous in their perch- 
ing habits to profit by highly specialized coloration. Some have transverse, 
opaque, obliterative bands of dark brown on their fair, transparent wings, 
which would otherwise often be made conspicuous by their unbroken glisten- 
ing. So also these flies' big, composite eyes are sometimes richly iridescent, 
and therefore, amid appropriate surroundings, well 'obliterated.' 

The slender-bodied Diptera, such as gnats, mosquitoes, 'long-legged dad- 
dies,' etc., show few or no very remarkable developments of protective color- 
ation. Being perchers on tree trunks, branches, and the dead-leaf covered 
ground, rather than on flowers and green leaves, they are usually dull colored — 
brown or grayish. Few have noteworthy body-markings, but many are 
obliteratively shaded. Their transparent (and often daintily iridescent) wings 
are sometimes marked with obliterative spots or transverse bands of dusky — 
as in some of the well-known and well-hated Anopheles mosquitoes, and some 
of the ' long-legged daddies ' or crane-flies {TipuUdcR) — while in others the wings * 
are dusky brown with various opaque white markings. In fact, with a good 
many dipterous insects obliterative wing markings largely take the place of 
body markings, and the two broad wings when flatly folded amply mask the 
body, from a top view. 

Wingless Hymenoptera, or ants in their apterous phases, largely lack not- 
able obliterative or mimetic (?) devices, apparently relying for defense on their 
strong biting jaws and sharp acid excretions, as well as their extreme bodily 
toughness, — and passing much of their time in dark retreats of their own 
making. Their prevailing color is black or dusky brown, without obliterative 
shading. But some are tawny yellowish, some rust-brown, and some wear two 
or three of these earth-colors (including black), in clearly defined, unflecked 
'ruptive' patches. Despite the sharply pungent acids they contain, — doubt- 
less effective against some predators, ants are a favorite prey (sometimes even 
the sole (?) diet) of certain birds and beasts, and it is somewhat curious that 
they have not more highly developed disguises. Protective coloration would 
not avail them, however, against the most greedily and exclusively f ormicivorine 

207 



creatures, the ant-eating mammals, who dig open their strongholds and devour 
them by the thousand at a meal. 

The Neuroptera (for convenience I follow the old arrangement and include 
the dragon-flies in this order) have, in the matters of outward form and dis- 
guising-coloration, much in common with the aerial insects already considered, 
but also a few salient points of difference. As everybody knows, the typical 
dragon-flies (Libellulidce) sit with their four large gauzy wings fully outspread 
in a single plane. Too finely-netted to be perfectly transparent, these wings 
(in addition to being iridescent) are very often marked with bold obliterative 
bands or spots of opaque color, like that of sticks and bark and shadows — 
brown, brown-red, dusky — and these markings go far toward making the 
wings invisible against their average backgrounds.* The long and slender, 
stick-like body also is often marked with obliterative cross-bars, and oblitera- 
tively shaded. For the true dragon-flies, unlike most of the insects we have 
been considering, habitually perch back-uppermost, — or sometimes vertically, 
but rarely or jiever upside down. Hence in their disguisement there is op- 
portunity for counter shading and picture-patterns to come fully into play. 
The patterns they wear are of many kinds and many colors (green, red, yeUow, 
blue, and black perhaps predominating), but almost all are transverse and 
most of them are very simple. Their counter shading of course takes in not 
only the attenuate abdomen but the thorax and big head; in short, the whole 
main form of the insect. The proportionately enormous compound eyes 
are usually rather dim-colored, but more or less iridescent, and very inconspic- 
uous. Gorgeous iridescent foliage-color — cold blue to golden green and 
yellow — is common in the costumes of dragon-flies, and highly characteristic 
of some groups. As they are bird-like in their light, upright perching and 
sudden, swift, aerial sallies in pursuit of their flying prey (from which dashes 
they often return to the same perch), so are they bird-like — ^though also like 
butterflies and lizards — in the splendor of their obliterative, vegetation-picturing 

* Their concealing-coloration probably serves them even more vitally in their aerial hunting 
than as a protection. — A. H. T. 

208 



costumes. The bodies (abdomens) of some kinds are so extremely slender and 
long that they are almost unrecognizable as belonging to an animate creature, 
looking more like grasses, sticks, leaf-stems, etc. Hence it would seem that 
they might also be subjects for complete mimetic disguise. And in fact, a few 
of the slenderest kinds have little or no obliterative shading, and present a close 
mimetic likeness to definite solid details of vegetation. Some of these ' mimics * 
are rich brown-red, like many of the sticks and twigs and weed-stems 
amid which they perch — others ochre-yellow like dead meadow-grasses, — etc. 
The wings, however, rarely or never contribute to the mimetic effect, but 
are almost always obliteratively marked, with various blotches and bands of 
average background color. Among the Agrionida — ^less typical dragon- 
flies which sit with wings folded, vertically and longitudinally — there are 
probably cases of mimetic resemblance in which the wings play a part. On 
the other hand, these exquisitely gracile and sometimes gay-hued Agrionidce 
are often equipped for obliteration — ^body, wings and all. Some which live 
always near water, usually perching close to its surface, have fair, bright-blue, 
obliteratively shaded bodies, which match their average watery backgrounds, 
under blue sky. Others have black, shadow-like wings, sometimes marked 
with a few obliterative white spots. On the whole, however, obliterative 
patterns, especially of the wings, are less in evidence among the Agrionida 
than among the Libellvlidce or true dragon-flies. 

Obliterative wing-patterns (both dark marks on light, transparent wings 
and light marks on dusky ones) occur also among some of the groups of plainer- 
colored Neuroptera, such as the caddises, mantispians, scorpion-flies, ephemera, 
etc.; though many of these insects, especially the smaller species, lack such 
markings. Some, on the other hand, are colored throughout much like some 
of the red or golden brown, obliteratively equipped true dragon-flies. In 
general, the coloration of the smaller and dingier Neuroptera differs but little 
from that of the corresponding dipterous insects. Few have highly specialized 
disguises of either color or form, in the perfect state, though most of them 
are obliteratively shaded. Nor, with a few exceptions, are the larvae or pupae 

209 



of these insects, or of any of the insect orders mentioned in this chapter, of 
much interest in the present connection. Such of them as are aquatic but 
not mud-haunting are apt to have obHterative shading, more or less complete, 
but their coloration is seldom or never highly specialized. The larvae of dragon- 
flies are mud- and dingy-bottom-colored, counter, shaded very scantily or 
not at all, and they are wont to lie concealed under mud or bottom-rubbish, 
leaving only their voracious heads exposed, ready for prey. Some hymenop- 
terous larvae (those of "sawflies," etc.) feed on leaves in the daylight, like 
lepidopterous caterpillars, which they resemble in many points of external 
appearance. But they have, as a rule, some active defensive (?) equipment 
(e. g., the power of jetting out pungent liquid), and their disguising coloration, 
in most cases, appears far less specialized than that of many caterpillars. 
(Some of these hymenopterous larvae, indeed, in the roUed-up attitude charac- 
teristic of them when at rest, bear a remarkable likeness to snail-shells. But 
this is very likely a mere coincidence.) For the most part, the larvae of the 
Coleoptera, Hymenoptera, and Diptera live hidden away from daylight and the 
attacks of the higher animals, except such as can dig or drill for them. Hence 
they are colorless, or monochrome, without patterns. In the case of insects 
whose metamorphosis is incomplete, like most of the Orthoptera, the earlier 
stages much resemble the later in their disguising coloration. 

Spiders 

Spiders (Arachnidce) assuredly rival insects in the variety and high devel- 
opment of their disguising costumes. But we have studied them even less 
than we have studied insects, and hence must pass them over even more briefly. 

There are wonderful developments of out-and-out mimicry among spiders. 
Many such cases have been described by naturalists, and many, doubtless, 
remain to be discovered. 

But 'obliteration,' not mimicry, is our theme, and obliteration is the rule, 
not the exception, in the disguisement of spiders. The many kinds which in 

2IO 



their perching have the requisite constancy of position relative to the prevail- 
ing light, are, in almost every case, obliteratively shaded. Thus their great, 
globular bodies are 'flattened out,' and, with the further aid of background- 
picturing patterns, of one sort or another, practically effaced. Some wear 
tree-bark and rock-surface pictures, more or less generalized, others leafy 
or grassy ground pictures. Those which swing free in flat, open webs have 
sometimes very bold and brilliant patterns — flower-like, dewdrop-like, and 
like black shadow-vistas amid small, sunlit vegetable forms. Some of these 
brightly patterned spiders have the upside-down habit, and their counter 
shading is of course inverted, like that of so many caterpillars. Some of 
them, with globose and highly colored abdomens, have slender, flat gray 
heads, duly counter shaded, which in time of watch and quiet are laid against 
a specially constructed patch or trail of glaucous, opaque web, which they 
match exactly. (See Fig. 127.) The big, round abdomen, meanwhile, is 
either separately but equally well 'flattened' by counter shading, and 'merged' 
by picture-patterns into its background of sunlight and shadow, grasses and 
flowers, or it presents a mimetic likeness to some single, solid landscape-detail 
— flower, berry, seed pod, or curled-up leaf. 

'Hole-picturing' (Chapter XXII, Fig. 120) is a common detail of disguise 
among the more richly patterned kinds. 

The dainty white spider* shown in Plate XVI, Figs. V, W, X and Y, well 
illustrates a fact to which we alluded early in the book, namely, the greenness of 
foliage-filtered sunlight, potent in its visual effect on animals' colors, particu- 
larly white. In some views amidst sunlit leaves, this actually porcelain-white 
spider (Figs. V and Y) looked even greener than Figs. W and X show him. 

The next and final chapter will treat scantily of the most beautiful and 
elaborately colored of all insects, if not of all animals, namely, the Lepidop- 
tera in the perfect state, or butterflies and moths. 

* This species has also a yellow phase. 



211 



CHAPTER XXVII 

BUTTERFLIES AND MOTHS 

/. Butierflies 

THESE gloriously resurrected "worms," these favorites of man from 
ancient times, — creatures which he has been wont to consider purely 
and simply bright and beautiful, — are in reality all tricked out in fine and 
powerful disguising-costumes, which make them, each in its own special 
situation and headquarters, invisible or scantily visible to their enemies. 
Famed though butterflies are for their gay and wondrous gaudiness, there is 
probably no single kind among them all whose coloration is not concealing, 
in its true and particular environment, under the typical and appropriate 
conditions. In civilized lands, species may and doubtless often do survive 
their fittest environments, when these are destroyed by man. Hence it is 
only in the primeval wilds — e. g., the great tropical forests — that the butter- 
flies and their proper surroundings can infallibly be found together, and their 
interrelationships rightly studied. Nor is it easy to imagine any pursuit in 
natural history more profoundly fascinating than the study of the special 
disguising-costumes of tropical butterflies. Even as the subject was known 
to naturalists who recognized only mimicry and an exceedingly limited range 
of more nearly obliterative "cryptic" color schemes, it was already a large 
and very interesting theme. But it has now grown beyond measure greater 
and more interesting, since by the disclosure of the simple laws of true oblit- 
erative coloration, it has been extended to include practically all butterflies 
and moths. 

If a man well fitted for the task were to devote his whole life to the study 

212 



of the disguising coloration of the butterflies (and moths) inhabiting say a 
few square miles of Brazilian forest, he would doubtless be discovering new 
wonders even of essential principle on the last day of his hunting. 

Our own knowledge of the subject is of the slenderest and most frag- 
mentary sort; nevertheless we can open several vistas into quite untrodden 
fields of exquisite truth. Some few of our readers are already familiar with 
my father's paper on "Protective Coloration in its Relation to Mimicryj 
Common Warning Colors, and Sexual Selection," * wherein most of his 
discoveries concerning butterfly coloration are clearly outlined. The present 
chapter contains but little which was not at least foreshadowed in the above- 
named paper, or in an article by me published in the Century Magazine 
for June, 1908, and the reader must take it as a recapitulation and enlarge- 
ment of these earlier essays. 

In the first place, the obliteration of butterflies is a ve'ry different problem 
from that of vertebrates, or even large-bodied insects. Obliterative shading 
is but scantily called into play, for their principal members, their wings, are 
flat and paper-thin. Their slim, cylindrical bodies are almost always counter- 
shaded, to perfection, but this is, comparatively, a small detail of their dis- 
guisement. Their great flat wings, with their characteristic outlines, have 
to be disguised by other means. In the case of birds and beasts, etc.. Nature 
has to use artifice and deception to make them into 'canvases' for back- 
ground pictures; but butterflies' wings are actually flat planes, all ready for 
the pictures. These Nature gives them, to the highest imaginable degree, 
ranging through a scale of variations marvelous in its immensity, yet fur- 
nishing each species with a costume well fitted to its own peculiar mode of 
life (although, as already explained, the perfection of the fitness may be 
no longer discernible, since it is often marred by rapid, man-vsrought changes 
in a butterfly's natural environment). 

This great agglomeration of differing butterfly types (as far as it is known 

♦Published in the "Transactions of the Entomological Society of London" for December 
24, 1903- 

213 



to us) may be separated, for our purposes, into several main groups, — such 
as that of sedentary and that of aerial species. The division is somewhat 
arbitrary, since practically all butterflies are strong of wing, and there is such 
a multitude of intermediates connecting the two types that it is impossible to 
draw a sharp line between them; nevertheless, the terms cover, in the aggre- 
gate, an essential difference of characteristics. Among the sedentary species, 
then, occur all the most highly wrought, minutely detailed "cryptic" pat- 
terns (a good many of which have been recognized as such by naturalists in 
general). They are worn by butterflies which pass most or at least very 
much of their time at rest, sitting motionless, with wings — in most cases — 
folded perpendicularly over their backs. Some of them are developed mimet- 
ically, even to an extraordinary degree — e. g., the, famous leaf-mimicking 
Kallima inachis, of India. There are many other pronounced though less 
extreme cases of whole-leaf mimicry among butterflies, not only in the genus 
Kallima, but in nearly allied as well as in some remote genera— and even 
among restless 'aerial' species. One such, which I believe has never been 
recorded, is that of the abundant and familiar South American Heliconius 
melpomene. On wing amidst the uniformly bright-green lower foliage of the 
tropical woods, it is as often conspicuous as any patterned butterfly could 
well be. [The gaudy costume of this red-and-black Heliconius is evidently one 
more example of coloration adapted to the wearer's moments of greatest danger. 
Haunting, while on wing, the thickest foliage, where birds cannot easily catch 
it, it is probably most in danger when intently feeding among flowers. (At 
such times butterflies sometimes allow themselves actually to be plucked off 
their perch by one's thumb and finger.) Probably this Heliconius finds such 
an intoxicating feast in the tops of certain great flowering trees that it there 
becomes an easy prey to any birds that want it.]* But in its nightly roosting 
(begun in the early twilight), it is a leaf -mimic, of no mean achievement. 
It roosts — as we have seen it — gregariously, several individuals (three to ten 
or more) occupying the same leafless twig, beneath which, at pretty regular 

* Interpolation by A. H. Thayer, 
214 



intervals, they suspend themselves, with closely folded wings. The under- 
sides of these wings, now alone exposed, resemble the upper sides in pat- 
tern, but are very much dimmer, the black being replaced by ochrous dusky 
brown and the red by soft, hoary pink. In addition, the lower wings are 
narrowly bordered on the anterior edge with pale yellow, and the slender 
body bears spots of the same color, while the bases of the fore-wings and the 
immediately adjacent portions of the body are marked with small red spots. 
Half of the broad pink ( = red) wing-band shows beyond the tips of the folded 
lower wings. The whole form of the insect thus folded and placed, though 
without any very peculiar modifications of contour, is almost exactly like that 
of many slender, entire leaves common in the forests it inhabits. But ob- 
serve, it is not like a living leaf in color, nor does it (in our experience) im- 
merse itself in a sea of foliage, there to be the single counterfeit among many 
genuine originals. Instead, as I have said, it selects, with several compan- 
ions, a leafless twig, in a spot where leaves are few, and together they suspend 
themselves beneath this twig in the semblance of a row of drooping dead 
leaves which still show traces of live color (the fine yellow lines and spots), 
and are each marked with a partly faded pink disease-spot (the pink band 
crossing the fore- wings) and some brighter red disease-flecks near the leaf's 
( = the butterfly's) base. That this resemblance is not fancied, but real and 
very potent, will, I think, be attested by anyone who studies the roosting- 
habits of Heliconius melpomene. There are doubtless many fine cases of this 
sort of mimicry still to be discovered. But, as we have repeatedly affirmed, 
mimicry is not our theme in the present book, wherein we must confine our- 
selves almost wholly to the far larger and more intricate problem of ohliter- 
ative coloration. Nor is it to be supposed that mimicry rather than obliteration 
is the rule in any large group of butterflies. On the contrary, the cases of 
out-and-out butterfly mimicry are relatively very few indeed, and scattered, 
while ' obliteration ' is universally and most variously achieved among them. 
Many of the butterflies which rest amid live foliage and flowers have 
daintily detailed and at the same time ' generalized ' pictures of their varie- 

215 



gated and varying backgrounds of more or less distant leaves, twigs, blossoms, 
etc., with their lights and shadows, and with vistas through the nearer back- 
ground to the further. Such patterns occur on both the upper and the under 
sides of the butterflies, but are usually minutest on the undersides. They are 
characteristic of species which sit with motionless folded wings — or in other 
words, those of the 'sedentary' type. Some of the South American species 
of the genus M'etamorpha, as M. dido, are good examples. So, of a some- 
what different type, is the European "Orange-tip" butterfly (Euchlce car- 
damines) whose floweret-picturing is well known. (See Fig. 128.) This 
is in part almost mimicry, though compound, for the nearer flowers look as 
near as the actual wing-surface on which they are rendered. 

More restless kinds, which alight only momentarily, keeping their wings 
outspread, or continually opening and folding them, have more generalized 
leafy or flowery background-patterns, often strongest on the upper side. 
These we will discuss more in detail later, when we have finished our frag- 
mentary review of the group of 'sedentaries' or closed- winged perchers, the 
butterflies whose most highly specialized obliterative coloration is on their 
under -sides. This group may be subdivided as follows: i. True leaf mimics 
(already mentioned, e. g., Kallima inachis and Heliconius melpomene.) 2. 
Those butterflies whose obliterative pattern pictures a varied background of 
live leaves, flowerets, and other richly colored details of living (and dead) 
vegetation (already mentioned, e. g., Metamorpha dido, and, in part, Euch- 
lce cardamines). 3. Obliteratively colored bark- (and rock-) butterflies. 
These are many, although bark-picturing patterns in their supreme develop- 
ment are more characteristic of moths than of butterflies. All ( ?) the multitu- 
dinous moths which are addicted to perching on tree trunks sit with wings 
flatly applied to the bark, whereas the butterflies of like proclivities, with a 
few remarkable exceptions, of which I shall soon say more, keep their wings, 
for the most part, perpendicularly folded, so that their background — that of 
their full side view — is necessarily much more variable. Nevertheless, many 
of these butterflies bear colors and minute patterns on their undersides which 

216 




Fig. 128. Four Orange-Tip Butterflies {Evchloe cardamines) on 
cow-parsley, showing the flower-picturing on their undersides, and 
the "cutting down" of their out spread topview to a flower-iike form 
by darkish tips. 

Photographed from nature by Percy ColliDS. 




Fig. 129. Butterflies on vegetation {Papilio ajax^ P. asterUis 
Jiasilarckia artem-is, and Argynnis idalia), their dark patterns 
merging with the shadowed portions of their backgrounds, leaving 
their light markings standing out like lighted leaf-and-flower forms, 
at various distances. 

Photographed from nature. (Dead butterflies). 





Fig. 130. Light-colored (pierine) butterfly with background shadow-pictures 
on the borders of the forewin^. 

Photographed from nature (dead butterfly). 



Fig. 131. Small Tortoise Shell Butterfly (Va- 
nessa vrticfE) outspread on stony ground". His 
light border-patterns carry the aspect of the 
background into his wings, disguising their real 
contours, and making him look like a hole over- 
lapped by lighted ground-details. 
Photographed from life by Cherry and Richard Kearton- 
Courtesy (Jassell and Co. 



are decidedly of the tree-bark (or rock-surface) type. These patterns are 
at once finer and less fine than those of the flatly-applied lepidoptera. Less 
fine, as they less minutely and exactly depict one especial type of surface in 
one especial view; more fine, in that they combine the elements of several 
varieties of background at somewhat varying distances, — the bark of the tree 
on which they sit, with its markings lessened by distance and foreshortened 
in extreme side view, front or side views of bark-surfaces on other, farther 
trunks or branches; or even still more extended vistas of the mixed forest 
background. Examples of this type, in full and simple development, are the 
several familiar northern butterflies of the genera Grapta and Vanessa, as 
well as many nearly or remotely allied tropical forms. Tree trunks, tree 
branches, and rocks are the characteristic resting-perches of these butter- 
flies, though they are by no means confined to them — any more than their 
patterns, beautiful and efl&cient for 'obliteration' though they are, show 
that ultimate touch of specialization which would best qualify their wearers 
for strictly specialized perching-habits. They are swift, sharp fliers, these 
Graptas and others, and their upper sides have as a rule wholly different col- 
ors and patterns from their lower, with different obliterative functions. But 
that is another story, to be told later in the chapter. 

Some of the much larger tree-trunk butterflies which habitually sit with 
folded wings, such as the famous Calligo eurylochus, and others of that genus, 
miscalled "Owl Butterflies," have a subtile obliterative pattern in which the 
picturing of near tree-bark is almost wholly replaced by that of more ex-, 
tended and diversified vistas of the brown forest interior — a pattern, in short, 
more like that worn by certain forest birds, such as the Ruffed Grouse. (See 
Plate II, and Chapter VI, pp. 38-41.) This accords with the fact that, owing 
to their great size, these butterflies can almost never have as a complete back- 
ground for their 'profile' the bark of the tree on which they are perching, 
as the small Graptas, etc., often can. (This is all the more likely on trees 
with rough and flaky bark — a condition more characteristic of northern trees 
than of those of the CalUgd's native forests.) The species of Calligo which 

217 



we have studied at large, perched, as we saw it, rather near the ground, often 
within a. few inches of it — and there are evident traces of ground-' picturing' 
in its beautiful mottled pattern. Thus it is something of a connecting link 
between the tree-bark butterflies and our fourth group of 'closed-winged 
sedentaries,' the ground- picturers. The variety in the at once epitomized 
and generalized ground-picturing patterns worn by these low-perching but- 
terflies is almost boundless, and it would be folly for us here to attempt any- 
thing beyond a brief general description of a few main types. Some of the 
species belonging to this group are haunters of open fields and meadows, 
and there is accordingly a frequent outcropping of grass- or even field-fiower- 
picturing in their costumes. But by far the greater number, at least among 
tropical butterflies, are sylvan, and the most prevalent feature of their widely 
varying patterns is the picturing of prostrate dead leaves and sticks. In one 
form or another, in more or less clear development, almost all the sylvan 
ground-perching butterflies wear these pictures. Such things as several dead 
leaves together, overlapping, each with a dark shadow underneath its border, 
blent softly on one side and on the other ending in sharp contrast against the 
bright edge of the leaf which casts it; leaves partly curled up, with holes and 
ragged borders, crowded and distorted in perspective; dull sticks with clear- 
cut shadows, bright, strawlike sticks standing out over broad, blurred shad- 
ows ; or objects like these combined into fine, sharply mottled patterns by per- 
spective, — such are a few of the commoner details of the unlimitedly various 
backgrounds of forest floor against which these butterflies are seen, when 
they are seen at all; and such, by the same token, and in very truth, are the 
details of their equally various and marvelously potent obliterative picture- 
patterns. Being such little creatures, and sitting so low down, they are secure 
of comparatively near backgrounds — ^relatively, for instance, to the species 
which perch high up on small twigs and leaves, or even those that sit with 
perpendicularly folded wings on tree trunks. On the other hand, their case 
is different from that of the flatly applied lepidoptera, whether moths or but- 
terflies, and whether of tree trunks or the ground, in that their backgrounds 

218 



are almost always at least a few inches distant from them, and subject both 
to much variety and complexity of detail and to a good deal of refinement and 
distortion by perspective. Some of them, indeed, wear rich, varied ground- 
scenery pictures, scarcely rivaled by those of the most finely patterned forest 
birds. Others are colored very simply, with either many very faint and 
delicate or few and bold obliterative markings. 

Passing now to the class of aerial butterflies, i. e., those which spend a 
much greater proportion of their time in flight, and do not characteristically 
"sit close" on perches, we find, of course, new general schemes of coloration. 
But as I said before, the two classes are by no means clearly separate, and 
hence their distinctive color schemes are subject to interminglement, of many 
forms. In the first place, most of the 'sedentary' wing-folding butterflies, 
such as we have been considering, are 'aerially colored,' so to speak, on the 
upper side. That is, their upper sides bear either such colors and patterns 
as decrease to the utmost possible degree their inevitable conspicuousness in 
flight, such as tend to obliterate the wings of the perching insect when they 
chance to be expanded, or such as 'dazzle' in the way mentioned in Chapter 
XXVI, p. 199, and of which the reader is soon to hear more. ('Dazzling'- 
colors of this kind, indeed, are confined, in their full development, to close- 
folding 'sedentary' butterflies, and, contrariwise, there are few such butter- 
flies whose upper-side colors do not on occasions perform this ' dazzling '- 
function, however largely obliterative may be their general use.) 

There are butterflies which alight very often, but do not stay long in one 
place, and either keep their wings outspread, or are continually closing and 
opening them. These, intermediate between the sedentary and the aerial 
types, share the color schemes of both, — ^perhaps inclining, in costumes as in 
actions, to the aerial. Their trick of wing-waving, however, is common, in 
more or less pronounced form, to most butterflies, — some of the tight-folding 
'sedentaries' alone being nearly exempt from it. (In conjunction with the 
less minutely detailed patterns of many of the species that practice this trick, 
it would seem to be a general measure for 'assimilation' with their surround- 

219 



ings — a movement imitative of the swaying and trembling of the nearly always 
breeze-blown leaves and flowers and twigs amid which they sit.) Even when 
perching, these butterflies of the 'intermediate' class expose the upper side 
as freely and fully as the lower, if not more so, and in many cases the upper 
side is the more specially and minutely patterned of the two. The prevailing 
color of all such butterflies, or at least the color which occurs almost unvaried 
on the greatest number of species, is dusky olive brown, — 'black' which is 
not black. This is just the average tint of the smaller shadows amidst vege- 
tation. On this groundwork of perfect shadow-color are painted all sorts 
of leaf, sun-fleck, and flower-pictures — more delicate and elaborate on species 
which more frequently alight, bolder and simpler on the more constantly 
aerial kinds. (See Fig. 129.) The commonest tint of the light ' picture '- 
markings, which stand framed in the pure, elusive shadow-color, is bright- 
(often somewhat greenish) yellow, — and this, after white, is the color of the 
majority of flowers. Furthermore, it is the color — ^barely clarified — of almost 
all brightly sunlit foliage. No wonder, then, that the presence of this color 
in clear and delicate generalized picture-patterns, with the due amount of 
contrasting, dusky shadow-tint, strongly tends to 'obliterate' the broad, flat 
wings of butterflies. So many and so various are these picture-patterns, in 
kind and in degree (of elaboration and finish), that it would be hopeless for 
us here to attempt a comprehensive account even of the main types of them. 
Here as elsewhere in our book, the description of a few characteristic cases 
must suffice. 

Papilio polydamas, of North America, and some of the dark Satyrina, will 
serve to typify the butterflies which have a shadow-like ground-color overlaced 
with bright, generalized pictures of living vegetation. Some of these, Papil- 
ionidce especially, have such patterns beautifully clear on the under as well 
as the upper sides, and often rest with tightly folded wings. The patterns of 
their under sides, in fact, though usually less bold and bright than those of the 
upper, are also as a rule more fine and delicate, as if to admit of a closer in- 
spection. And in truth it is chiefly at times when the butterfly has relaxed 

220 



its vigilance and is sitting more or less inert, that the pattern of its under- 
side is displayed in full. Also, the side view is apt to have a somewhat more 
distant background than the full top view,* and hence requires a more deli- 
cate pattern for 'obliteration.' 

Sun-flecks are another important feature in these picture-patterns of the 
NymphalidoR, etc. They are big circular marks of yellow or whitish, some- 
times rimmed with violet or blue, and set in leaf-shadow color. The blue 
border is a mere intensified rendering of the sky-tinged rim around real sun- 
flecks, which are in fact camera-obscura images of the sun surrounded by 
blue sky. Such markings are worn for instance by Nymphalis bolina and by 
the male of Hypolymnas misippus. Usually, as in the case of H. misippus, 
the encompassing dark tone (with or without a skyey rim) ends in sharp 
contrast against the spot; sometimes, however, it is blended into it, as is the 
case with real sun-flecks also. Then there are swi-streak pictures — ^mark- 
ings that depict sharp ribboiis of sunlight alternating with bands of dusky 
shadow. Patterns of this kind are a most characteristic element of some 
woodland scenes, particularly in tropical woods, amid fringed palm leaves, 
and other, smaller, finely pinnate foliage, — and bright pictures of them are 
worn by some of the butterflies inhabiting these forests. Heliconius chari- 
tonia, of the West Indies, etc., is a fine example. Indeed, the disguising- 
coloration of this or a closely allied butterfly has been, ere now, in part, well 
and accurately analyzed and described — ^by Mr. C. W. Beebe, of the New 
York Zoological Park. But such a costume as Heliconius charitonia wears 
is not limited to the single function of still-sun-stripe-and-shadow picturing 
described by Mr. Beebe, admirably though it serves that function. It is also 
highly ' obliterative ' as the Heliconius flies about rather slowly amid feath- 
ery, sunlit foliage. The irregular and not rapid motion of the butterfly's vividly 
striped wings fits into and merges with the mazy scintillations of the fine-cut, 

* Because the butterfly is likely to be in closer contiguity with the nearer details of its back- 
ground when flatly outspread, than when folded and projecting outward perpendicularly from its 
perch. 

221 



waving leaves, sunlit and bright above dark shadowy interstices. Again, 
when the Heliconius is quietly perching, its yellow marks may produce the 
effect, additional to that described by Beebe, of vistas through shadows or 
dark twigs to a more distant sunny background. In fact, this effect is inter- 
changeable with the other (that of light details or marks laid on or standing 
above a shadowy background) in almost all the numberless obliterative pat- 
terns of this general character, both on butterflies and on other animals. 
According to the creature's position and the character of its background, at 
any given moment, its pattern will incline toward one or the other of these 
two equally deceptive and obliterative effects. 

The beautiful South American Metamorpha dido, already mentioned 
among 'close-folding sedentaries' wears on its upper side a bolder green- 
and black-laced pattern, which makes it extremely 'dim' and elusive in its 
flight amidst foliage. But this pattern must also on occasions serve the but- 
terfly at rest, for though cruder than that of the underside, it is too delicate 
in detail to be merely a flight-pattern. For flight of course tends to cancel 
the visibility of markings, blurring and blending forms and colors, and even 
on the most slow-moving butterflies only big, bold patterns can maintain 
a clear effect in flight. Many of the more aerial butterflies have such big, 
bold patterns, however. In addition to the t5^es described and figured 
above, those represented by some of the other HeliconidcB, and some of the 
South American green and black and red PapilionidcE, are notable. A but- 
terfly thus patterned with black and yellow (e. g., Heliconius sara), or with 
black and green and red (e. g., Papilio gargasus), will never at any point in 
its airy course relieve clearly, in full contour. As it passes across shadowy 
interstices amidst vegetation, its black will disappear, leaving in sight only a 
skeleton pattern of yellow, or green and red; and while it is passing brightly 
lighted leaves and flowers only the black will show. Thus the watching eye 
is condemned to see only flickering glints of color, instead of seeing the whole 
form of the moving insect, as it would were the insect monochrome. Such 
constantly repeated metamorphoses of aspect, amid the vegetation's varying 

222 



movements, must strongly tend to baffle a pursuer. Heliconius melpomene has, 
as I have already mentioned, a still simpler 'ruptive' flight-pattern (on its upper 
side), and one which seems but poorly fitted to disguise it among green leaves 
alone. Some of the beautiful Hummingbird Papilios of South America have 
much the same coloration, with the addition of a pair of sea-green or pale-blue 
spots. Such are Papilio gargasus and several kindred species. This colora- 
tion is admirably fitted to disguise its wearers when they hover, hummingbird- 
like, over, or momentarily perch on, gay-colored and brightly lighted flowers 
which relieve against shadowy underspaces. But Heliconius melpomene, as we 
have seen it, is less of a blossom-haunter, and with its still simpler pattern, of 
black and red alone, it is not always as inconspicuous, even in its transitory 
flower-attendance, as patterns could make it, — as patterns in fact do make 
many of its relatives.* Like the Scarlet Tanager, however, and other some- 
what anomalously costumed woodland birds, melpomene is a haunter of dense, 
protecting foliage. Through the mazes of woodland greenery it threads its 
rather leisurely way with wonderful adroitness, flying with short wing-beats 
and much sailing, and its skill in dodging in and out and round about amid 
leaves doubtless makes it a difficult quarry for flycatchers. There are many 
other remarkable South American tropical butterflies of the same long-winged 
type. Especially noteworthy are those of one of the so-called "Batesian and 
Miillerian mimicry groups" — such species for instance as Lycorea atergatis, 
Tithorea megara, Mechanitis veritabilis, etc. Their general scheme of colora- 
tion shows much affinity with that of Heliconius charitonia, and much also with 
that of certain t5^es of the terrestrial tight-folding class. So also in their habits 
they are nearly midway between the two extremes. They perch low down in 
the forest, often very near or even on the ground, and their costumes contain a 
good deal of rich ground-brown — the universal brown of the tropical under- 
world, described in Chapter XIX. But though not, like Heliconius charitonia, 
sara, melpomene, etc., truly 'aerial,' they are restless, and spend much time on 
wing, often rising into the borders of that region of abundant foliage and fre- 

* See the interpolation on p. 214. 
223 



quent sunbeams which is the headquarters of sara, and other yellow and black 
or green and black 'aerial' butterflies. In their perching, too, they show 
infixitude of habits, often sitting with wings closely folded and sometimes 
with wings more or less expanded. Their upper and lower sides are much 
alike, but the lower has usually a somewhat finer pattern, which is highly 
'obliterative,' although less definitely and minutely 'ground-picturing' than 
most of the patterns worn by true terrestrial 'sedentaries.' In fact, the 
costumes of these more sluggish "heliconoid" butterflies contain just such 
a compromise between bolder obliterative flight-patterns, in foliage and sun 
and shadow tints, and finer, brown-ground-picturing perch-patterns, as a 
knowledge of their habits would lead us to expect. The supposed mimetic 
interresemblance of these butterflies' costumes was alluded to, though not 
specifically, in our Introduction. Another group of South American butter- 
flies, believed to show the same sort of mimicry is made up of species with 
more or less transparent wings. These also are aerial, their wings are long, 
and marked, in various patterns, with opaque bands and spots of dusky, or 
sometimes brighter color, inclosing spaces of pure glassy transparency. Of 
course these insects are normally almost invisible, not only when they sit still 
(with a background of green leaves or brown ground, or what-not) but even 
in their leisurely flight through the forest aisles. "One of these clear-wings," 
says Bates, the great English naturalist, in his wonderful book "A Naturalist 
on the Amazons," "is especially beautiful, namely the Hetcera esmeralda; it 
has one spot only of opaque coloring on its wings, which is of a violet and 
rose hue; this is the only part visible when the insect is flying low over dead 
leaves, in the gloomy shades where alone it is found, and it then looks like 
a wandering petal of a flower." 

Iridescence plays a great part in the 'obliteration' of butterflies, especially 
aerial ones. Indeed, splendid iridescent colors are enrolled in the service 
of the more restless butterflies with an amplitude and variety scarcely to be 
matched in the world of birds. We have already (Chapter XVI) given a 
general analysis of the obliterative power of highly changeable color. The 

224 



reader will readily perceive how well adapted butterflies are to profit by this 
factor of disguise. Though prevalent in almost all the main butterfly groups 
already named, and often playing a part in minute picture-patterns, lustrous 
changeable color reaches its highest development among aerial species, and 
especially those of the skyey over-realm of tropical woods (Chapter XIX, pp. 
107-108). Its range of tint is chiefly from reddish purple to golden green — a 
scale which includes aU the hues of open sky and sunlit foliage, and glowing 
interstitial shadow. Sometimes, for instance, as in the case of some of the 
big South American Morphos, almost the entire upper surface is covered with 
immaculate iridescent color. These glittering blue butterflies are for the 
most part highly aerial, and their color works like that of the peacock's neck 
(see Plate I), matching, in flashes, sky and sky-lit foliage, etc. Some of them, 
on the other hand, are also much given to perching low down in the forest, 
and here their vivid blue, in cooperation with their brown, picture-patterned 
undersides, achieves 'dazzling coloration,' of the active, metamorphic sort. 
The bright color of such species is apt to be less iridescent and shiny than 
fixedly lustrous, shifting somewhat in minor tints and in intensity, but in 
main effect staying always blue, whereas the blue of the more aerial and tree- 
top-haunting Morpho anaxibia, for instance, shifts to purple and to green in 
vivid play and interplay of keen metallic tints. The 'dazzling' effect pro- 
duced by some of these Morphos' costumes is often most pronounced. Imag- 
ine watching such a butterfly as it sails along through the brown aisles of a 
South American jungle. Its broad, immaculate blue wings look almost lu- 
minous in their glaring brightness, and the eye follows them easily and fasci- 
natedly along their course. Suddenly the butterfly alights, folding its wings 
sharply together, and — is no more. The eye must be well trained indeed to 
recover from its 'dazzlement' in time to mark the insect down exactly. It is 
like trying to see clearly after staring at the sun. More than this, the abrupt- 
ness of the metamorphosis, the instantaneous eclipse of the bright thing which 
the eye has been following, has in itself a very confusing effect. The butter- 
fly sits motionless, and will not stir its folded, dark-brown wings, covered with 

225 



forest-pictures, until its disturber comes within a few feet or even inches of it, 
when it expands them suddenly and goes flashing off through the forest, only 
to repeat the trick. This kind of 'dazzling' is doubtless a frequent factor, 
of greater or less relative importance, in the disguising coloration of butter- 
flies, and also of moths, which we shall presently consider in some detail. 

Lesser iridescence — the soft, masking sheen of bright, or especially of 
dusky, markings, is common to a vast majority of butterflies — as, indeed, of 
highly patterned animals of all classes. Its obliterative effect is constant and 
essential. Such lustre of dusky markings in a butterfly's picture-pattern is 
frequently offset by a complete sheenlessness of the accompanying light-col- 
ored stripes or spots, and this combination is potent to 'obliterate.' For the 
dark parts, with their ever-varying play of soft rainbow-sequences of tint, 
together form, as it were, a sort of fluid medium, a positionless, mutable at- 
mosphere, in which are suspended the definite and sharp details of the pic- 
ture-patterns, with their fixed positions. Or, to express it still more figura- 
tively, the butterfly has first been converted into space, and then that space 
furnished with such material details as it should normally contain. Not 
merely among butterflies, but throughout the animal kingdom, such minor 
lustrousness is a common and important factor of obliterative pattern. A 
perception of its use is indispensable to a full understanding of obliterative 
coloration. 

So far we have considered butterflies' patterns chiefly with regard to their 
ultimate effects of 'background-picturing.' We must now examine more 
particularly the principles which underlie these effects, the principles of the 
intrinsic ' obliterativeness ' of patterns. These have been touched on in our 
earlier chapters, but since many of them show up in much clearer application 
in the costumes of butterflies than in those of any other animals, they shall 
here be described anew. The term 'dazzling coloration,' in its widest 
sense, might include them almost all, for they almost all deal with devices 
and systems of devices for the reduction of one form's or detail's conspicu- 
ousness by the blazoning of some other detail. The butterfly's organic form 

226 



possesses characteristic actual contours and internal details; these, if the 
butterfly is to elude the eyes of its enemies, must be made as inconspicuous 
as possible. How should this be done — how has Nature done it? By the 
introduction of sham details, of such plainness, and so bestowed on the but- 
terfly's surface, as to eclipse and neutralize the real but faintlier showing 
details and contours. The stronger the pattern appears, the dimmer appear 
the forms and outlines of its wearer — as the reader has been shown. Patterns, 
then, in the obliterative costumes of butterflies, are so placed as fundamentally 
to thwart the conspicuousness of their wearers' forms; and, at the same time, 
the resultant effect of these intrinsically 'dazzling' and 'obliterative' mark- 
ings, under the normal conditions, is of perfect ^'c^^re-pattern. These two 
principles, in fact — if indeed they can be called two — work in practically 
inseparable combination and cooperation. Thus is achieved for butterflies 
the highest possible degree of average inconspicuousness — as, indeed, it is 
achieved for the many other t)^es of animal we have considered. Only, the 
case of butterflies is simpler, because the third great principle, obliterative 
shading, being confined to their bodies, plays, as to area, a comparatively small 
part in their disguisement. 

Let us look at a few concrete examples of these more subtile phases of 
'dazzling '-coloration. There can be no doubt that the entire arrangement 
of markings on the most brilliantly and elaborately patterned of butterflies 
is hostile to the conspicuousness of the insect's general form: let us then con- 
sider some of the details of this 'eclipsing '-system. Among the markings 
whose function is the masking and 'breaking' of external contours, two are 
especially notable. One is the diagonal cross-band at or very near the end 
of each fore- wing, which 'cuts off' a bigger or smaller tip, thus marring 
the characteristic outline; the other is a band, or more conmionly a series of 
spots, following more or less closely the real contour, in just the right position 
to neutralize the real contour's conspicuousness by distracting the eye's atten- 
tion to the a«/«-contour's vivider details, which serve as background-pictures, 
and are as a rule supported in this effect by other and more varied internal 

227 



patterns. Dark is conspicuous against light, and vice versa — accordingly, 
light-colored butterflies are apt to have dark tips and borders, with such in- 
ternal contours as work to bely the insect's form when these markings 'merge' 
with dusky backgrounds, while dark-colored butterflies are apt to have cor- 
responding light-colored markings. (See Figs. 130-131.) As we have seen 
in earlier chapters, a living animal in nature is subject to momentary vicissi- 
tudes of dark and light 'relieving.' When one side of a bird shows dark 
against its background, the other side, seen from the opposite direction, is 
very apt to be 'relieving' light. Hence, in very many cases, the best a crea- 
ture can have in the way of generalized disguise is the clearest development 
of 'ruptive' pattern, made of sharply contrasting light and dark marks. It 
is this 'ruptive' effect that seems chiefly aimed at in the costumes of many 
butterflies, though the resultant appearance is nearly always of adequate 
'picture '-pattern. Their background is to be a changing patchwork of 
dark and light, and they themselves are to be both shadowed and lighted, in 
rapid, ceaseless alternation; hence they must wear both dark and light in 
sharply contrasted, form-belying patterns. 'Tip-clipping' bands of dusky 
are very characteristic of light-colored butterflies, including some which bear 
a mimetic likeness to single flowers. Of such mimics there are doubtless 
many. But this flower-like-ness is seldom or never minutely perfect in the 
sense of the leaf-like-ness of Kallima, though sometimes very effective. Cases 
of this sort may be found among field butterflies, notably the Pierince. These 
are usually yellow or white — the commonest colors of flowers — with scanty 
markings. Their fore- wings, however, in the cases in point, are 'clipped 
down' to a shape more normal to flower petals by diagonal dark tips. That 
is, these tips, being of the regulation 'interstitial shadow color,' strongly 
tend to look detached from the light-colored wings, and merged with the shade 
beyond. Often these dark rims or tips — as also others of the larger shadow- 
picturing patches of dark color on butterflies — contain small markings; dim 
ones, like faint pictures of more or less distant plant-details in shadow; bright 
ones, like lighted near details above the shadow; pure white dots which 

228 



look much like little gleaming dewdrops. Another characteristic marking of 
these light-colored, flowerlike butterflies is a quartette of small dark flecks— one 
fleck near the middle of each wing — which form, with the two club-tips of the 
antennae, when the insect is symmetrically outspread, an almost perfect circle. 
These six little marks look much like stamens, and greatly enhance the flower- 
aspect, which often is yet further helped by a dusky clouding of the inner 
portions of the wings, blending outward into light and inward darkening 
toward the dark body; all of which produces a flowerlike appearance of 
concavity. 

But to return to the subtler 'dazzling' coloration of the background- 
picturing butterflies. One more important special marking of this kind must 
be considered, namely, the so well-known 'ocellus' or eye spot, a marking 
which occurs in many forms and on many animals, but probably reaches its 
highest development among birds and butterflies. At its full, as it appears 
on the Argus and Peacock Pheasants, and on several butterflies, an 'ocellus' 
is a clear and strong representation of a sharply shaded sphere, or even of a 
ball and socket, forms which may fairly be said to represent the quintessence 
of substantiality. Among ocellus-bearing butterflies, the genus Calligo is 
particularly notable. Some of the members of thi3 genus, such as C. eury- 
lochus, are popularly known under the misnomer of " Owl Butterflies," from 
the remarkable but undoubtedly fortuitous (?) resemblance of their under- 
side, when the wings are outspread, to the face of an owl, with wide-open eyes. 
The CalUgos have already been mentioned among close-folding butterflies 
whose undersides bear an exquisite picturing of more or less extended brown 
forest views. In the midst of these finely marbled forest-pictures stand the 
big, black-and-yellow eye spots, one on each hind wing. Except in flight — 
when, indeed, the markings of the underside are so shadowed and jerked 
about that they have little effect of any kind — only one ocellus can be seen 
at a time, for the perching butterfly always (?) keeps its wings perpendicularly 
folded. Each obliteratively-patterned side bears its one bold ocellus, which 
acts as a loadstone or 'dazzler' to the sight, diverting it from the faintly- 

229 



traced outlines of the wings, and helping all the faintly-patterned part of their 
broad surface to 'melt away' into the background. (See Fig. 132.) The 
sharply visible ocellus, therefore, either seems to be standing alone in air, or, 
more characteristically, 'recedes' with the rest of the wings' surface, and passes 
for a detail of the background. In either case, although in itself highly visible, 
it looks like nothing edible to insectivores, while by its very brilliance it masks 
and hides the organic forms of its wearer. Such is probably the main use of 
major ocelli in the disguising costumes of butterflies. Minor ocelli are often 
purely and simply details of background-picturing. Some, for instance, seem 
closely imitative of gleaming dewdrops, and of dewdrops surrounded by shadow, 
while others look like holes in leaves — dead or living, as the case may be. Some, 
especially of moths, are actually transparent. Between minor and major ocelli 
there is a smooth gradation, a complete chain of intermediates, and here as in 
all such cases it is impossible to know just where one function ceases and the 
next begins. Indeed, the two functions are more or less coordinate and inter- 
woven throughout this whole gradation, for the biggest, most specialized 
'dazzling' ocellus achieves its full service only when it passes for a detail of the 
background, and, on the other hand, the smallest accessory detail-picturing 
one has a share of intrinsic obliterative or 'dazzling' effect.* 

The multifarious obliterative devices of color and pattern worn by butter- 
flies and moths are often seconded by modifications of external form, by 
appendages, as in the case of birds and other animals. But the lepidopter's 
appendages are much more limited in kind, consisting almost exclusively of 
modifications of the outer edges of the wings. These are cut-in, in gentle 
curves or sharp, angular notches, or extended outward in longer or shorter, 
broader or narrower 'jags' or "tails," of many forms; in short, they are altered 
much and variously from the simple, average butterfly-shape. On the other 
hand, may it not be that even the 'normal' butterfly wings, so grotesquely 
large for the body, and so wonderfully marked for obliteration, are themselves 

* This book aims to discuss only concealing-functions, though not forgetful of the obvious un- 
limitedness of the uses that Nature must make of every detail. — A. H. T. 




Fig. 132. "Ocellus" or eye-spot ou a butterfly model. 'Dazzling' effect, etc., see page 230, chapter XXVII. 

'rhe ocellus distracts the eye's attention from the contour of the cardboard butterfly on which it is painted, and which, by likeues.-^ of shade and 
color, 'merges' with its background ; also, the ocelUis itself, when the butterfly is not detected, seems, necessarily, to be a detail of the ba ■kifnnind. 




Fig. 133. Moths, butterfly and pheasant's tail resolved by picture-pattern into representations of twies and leavps 
projecting over holes and shadows (Cf. Fig 120.) Polyphemus moths, 55, Proniethea moth C, Antiopa butterfly J) CvnthS 
moth A, and Copper Pheasant's tail E. ' r j , v^juwim 



obliterative 'appendages'? For the wings of most lepidoptera, and of all 
butterflies, are, judged in comparison with other aerial insects, and even the 
most aerial of birds, out of all proportion to the size of their bodies. A butter- 
fly with a wing expanse of about seven square inches weighs about a tenth 
of an ounce, or less; a bee of about the same weight, with highly aerial habits, 
has a wing expanse of only about a third of an inch; and a much-flying bird, 
e. g., the Red-tailed Hawk {Buteo horealis), weighing about forty ounces, has 
only about four hundred square inches of combined wing and tail expanse. 
In other words, the butterfly has about twenty times the flying-spread of the 
bee, and at least seven times that of the hawk, in proportion to its weight. 
Indeed, a butterfly is so greatly ' overwinged ' as to be incapable, in most cases, 
of steady or swift flight. Its big vans float and flutter like wind-borne leaves, 
carrying the little body which wields them in a tortuous, uncertain course, and 
making it bob up and down with every stroke — a puny and unstable fulcrum. 
To one who recognizes the power and importance of obliterative coloration, 
it seems by no means unlikely that this monstrous expanse of wing among 
butterflies (and some moths) is actually in itself an obliterative device — that 
its chief use is the delusive and effacive extension of the little edible butterfly 
outward into the environing vegetation and the background scenes. In 
every case(?), the little body itself has the very acme of obliterative coloration, 
based on complete counter shading. For the side view, when the wings 
are perpendicularly folded, it is often daintily picture-patterned; in a top 
view it is usually the center of dimness in a dim, smoky, blended patch of 
pale half -shadow tint. Literally the center of dimness — the dimmest and 
least noticeable part, from which the eye is led outward to the more or less 
bright markings of the widely extended wings. But these bright markings 
themselves are, as we have seen, potent parts of the disguise, since they picture 
the landscape, and lead the beholder to think he sees through and beyond 
where really there is an opaque surface interposed. 

Here, then, is an amusing contrast between old ideas and new. On the 
one hand, a butterfly is hailed as the very embodiment and epitome of gay, 

231 



bright, careless life, — a dancing elf, a creature beautiful for beauty's sake 
alone, a reveling fellowship of four animated, glittering, flowerlike wings; 
while on the other hand, if we follow this new supposition, we see a butterfly 
as a harassed mite of vitality, for harsh need's sake encumbered with huge, 
masking shields, richly enwrdught with illusive pictures of the scenes amidst 
which the mite of vitality dwells. The bee's wing and the hawk's wing are 
evidently formed for action, and for action only, whatever superimposed 
disguises they may wear; the butterfly's wing, at the present stage of its de- 
velopment, seems almost rather to be a mask which is also used for action. 
No doubt, however, butterflies are also protectively served in a still more 
direct and simple way by the disproportionate bigness of their wings — namely, 
by the actual elusiveness to winged insectivores which their consequent tor- 
tuosity and jerkiness of flight insures them. Watch a bird chasing a flying 
butterfly (which, by the way, is a decidedly uncommon happening — as if 
birds had learned the futility of such chases), and you will see how great is 
the butterfly's advantage, in spite of his offering a far broader target, over 
the "wheeling" beetle or even the swift, straight-flying bee. His body bobs 
up and down between his wings, and his wings carry him in a crazy, zigzag 
course — baffling, as a rule, to the most adroit 'dodgers' among birds. 

Among the butterflies whose big, picture-patterned wings have in addi- 
tion highly diversified contours, familiar examples are those of the genera 
Grapta and Vanessa, etc., often caUed "Angle wings," and the "swallow- 
tailed" Papilionidce. 

II. Moths 

There are also many long-" tailed" moths, like the great pale-leaf -green 
Luna {Actias luna) of North America, and the beautiful, diurnal, butterfly- 
like Urania moths of South America, etc. These Uranias are not only diur- 
nal, but preeminently aerial, spending the daylight hours largely in swift 
and tireless flight above and through the forests. They are marked — rather 

232 



more minutely than one would expect them to be — with black, or dark 
shadow-brown, and iridescent green-blue, green, or golden bronze. Judg- 
ing by the fineness of their rich obliterative patterns, as well as their pro- 
nounced appendages, the "tails" on their hind- wings, we must suppose these 
moths to have habits of quiet diurnal resting or feeding, of which we know 
little or nothing. But the "tails" of some of them, e. g., the most beautiful 
Urania leilus (called in Trinidad the "Green Page"), undoubtedly serve 
them in flight, in the manner of the tails of peacocks and pheasants, etc. 
(Chapter XVII, p. 95) — Pleading enemies to strike behind them. For these 
tails are white (brightest at the tip, and forward blended into green), and the 
most conspicuous part of the moth in flight. Like the tails of certain newts 
and lizards (which also, as we have seen, are often thus 'dazzlingly' and 
'distractively' colored), these white appendages can even be seized and torn 
off without grave injury to their possessor, who thereafter merely wants one 
safeguard. Doubtless, however, they often cause the attacker to strike en- 
tirely behind the moth. A like use, among others, is evidently subserved by 
all rear-end appendages of moths and butterflies — especially aerial ones, and 
especially when the appendages are very light colored, or transversely marked. 
Indeed, the same service is no doubt rendered even by the light- or bright- 
colored hind wings foiled by dull fore-wings, so very common among moths, 
although other effects of this combination are probably of more importance. 
It constitutes, for instance, a true 'eclipsable dazzling costume,' exactly 
corresponding to that of many butterflies. For as the butterfly, alighting, 
hides the dazzling-color of its upper side by folding its wings perpendicularly, 
so the moth alighting hides the dazzling-color of the upper side of its hind 
wings by folding its fore-wings flatly over them. Yet even this is probably 
only a subsidiary function of such markings of moths. If they catch the eye 
when the moth is flying, they will abet his 'vanishment' when he alights by 
their total and abrupt eclipse. Yet their main tendency is probably the 
reduction of their wearer's conspicuousness in flight. They are, in fact, oblit- 
erative flight-patterns, like those worn by aerial butterflies. If a creature is 

233 



to fly amid surroundings much and brightly variegated, he will be the less 
conspicuous the more bold samples of his environment's varied spots and 
colors he bears on his own surface. Such an enrichment of attire for greater 
average inconspicuousness in flight has Nature furnished many moths, on 
the hind wings. When, as is common enough, these are mainly whitish, or 
of some very pale color, they serve a still more definite obliterative purpose, 
and that by night as well as, or rather better than, by day. Like the white 
sterns of ruminants and hares, the white back-patterns of grubbing nocturnal 
carnivores, etc., they often nearly or quite match the sky. Thus a white- or 
pale-hind-winged moth retreating in free air, especially at night, will often 
be quite undistinguishable against the sky, while one with dark hind wings 
would be plainly visible. But many have dark hind wings, or hind wings 
with strong dark markings, and such a coloration seems meant for daylight 
rather than for night-light use. Indeed, though most moths are almost 
wholly nocturnal, their costumes, with few exceptions, are doubtless specially 
adapted to diurnal use. For most of them pass the day in the open air, sitting 
motionless, flatly folded, on tree trunks, rocks, grass blades, dead or living 
leaves, or the brown, leaf-strewn forest ground. It is chiefly against dis- 
covery by daylight in such-like situations that the intensely high-wrought 
"cryptic" coloration of their upper sides avails them; as the often far simpler, 
brighter, and more boldly variegated coloration of the hind wings, wholly 
hidden while they are perching, avails them when, disturbed, they are forced 
to make a daylight flight. 

But the special forte of moths' coloration lies in their finely wrought hid- 
ing-patterns, which, for specialization and variety, for marvelous minuteness 
and obliterative potency, are not to be surpassed and scarcely even to be 
equaled in any other branch of the entire animal kingdom. These patterns 
differ from the corresponding ones of butterflies (all but the few flatly-applied 
kinds, like the South American and West Indian "Creaker" (Ageronia fer- 
onia, etc.), whose bark- and lichen-pattern is almost as exquisitely and mi- 
nutely wrought as that of any moth), just as their wearers differ from the 

234 




Fig. 134. Two grass-moths. (Dead 
grass.) Compare Fig. 13S. 
Photogrraphed from nature (dead moths.) 



Fig. 1.36. 





Fig. 135. Tiger-moth on sprig of box. Compare with Fig. 134 a. 
Photographed from life hy Cherry and Richard Kearton. Courtesy Cassell and Co. 





Barli-moths of the finely-grizzled type. Fig. 136, four on maple bark. Fig, 137, two on pitch pine. Fig. 138, three on gray birch. 



butterflies in habits. They are far more fixed and still, in their daylight 
perching, and they sit -jiatly applied to their perches, instead of standing out 
from them perpendicularly. Thus they are fit subjects not only for higher 
particularization and greater minuteness of pattern, but for direct, near, flat- 
surface-picturing costumes, from which the element of pei'Speciive--pictunng 
is largely excluded. Naturally, this rule has exceptions. There are ground- 
perching moths — grass moths — for instance, covered with representations like 
the Rocky Mountain Ptarmigan's (Figs. 40 and 41 of Chapter VII), of dry 
grass blades crisscrossing over a background of shadow. Such a moth is 
shown in Fig. 134, A. Perching among slender grasses some inches above 
the earth, a moth like this has often a background full of diverse distances, 
of little 'vistas' — ^and it is patterned accordingly. This, indeed, is not an 
uncommon tj^e of coloration among moths, and there are many variations 
on it. Kindred pattern-schemes occur also among woodland moths — both 
terrestrial ones, which perch on fallen dead leaves, and those that are wont 
to sit in trees, on green or withered foUage still unf alien. (See Fig. 135.) 
But the vast majority of moths habitually sit pressed close against a flat or 
flattish surface, which wholly hides their undersides, and prevents their hav- 
ing any more distant background, except in extreme side view. The aspect 
of this flat surface is pictured on the shielding upper sides of the moth's 
fore-wings, and on its head and thorax, — or, in the case of species which sit fully 
outspread, on both fore and hind wings, and the entire upper surface of the 
body, — often with an almost microscopic particularity of detail. Only the 
slightest reduction from the real size of the imitated details is needed in this 
picture-pattern, for the space between picture and model is almost nil. In- 
deed, though we may pretty safely assume, in view of Nature's prodigal per- 
fectionism, that the moth's pattern is thus as it were 'focused' for the very 
closest average unison with its background, the difference and its adjustment 
are often too slight for man's eyes to recognize with certainty. But there 
can be no doubt that the coloration of these flatly-applied moths is on the 
whole ohliterative rather than mimetic; that, in other words, such a moth 

235 



characteristically seems merged into the flat plane on which it sits, rather 
than showing its real, slightly raised form and passing for an inanimate excres- 
cence. Of course, however, this rule has exceptions. Any such moth must 
sometimes, especially in side view, present and profit by the mimetic instead 
of the ehliterative aspect; and there may be some moth-costumes which have 
been developed for full and elaborate mimicry of this kind, at the expense of 
'obliteration.' But that this is exceptional* is amply shown not only by the 
character of most moths' patterns, but by the complete obliterative shading 
which their usually plump bodies bear. This can be seen to best advantage 
on the very large-bodied kinds, notably the hawk moths (Sphingidce); but 
— supposititious mimetic moths aside — ^there are almost no species that lack 
it. Usually the bodies are not only counter shaded, but marked with oblit- 
erative patterns — either such, already mentioned, as cooperate with the back- 
ground-pictures on the wings, or bolder 'secant' and 'ruptive' patterns which 
tend to obliterate the bodies in side view, when exposed to sight below the 
wings. A similar service is rendered by the more or less abortive patterns 
of the under sides of the wings, which are usually dim and imperfect counter- 
parts of those of the upper sides. In most cases, they are normally quite 
hidden while the moth is perching, and their frequent comparative crudeness 
seems therefore to be in just proportion to the smallness of their use. In 
flight they are of course exposed — though much less clearly than the upper-side 
patterns, because masked by shadow — and they then, especially in the cases of 
the brighter and bolder ones, have a distinct share of obliterative effect. On 
the other hand, the prevalent paleness of the under sides of the wings must be 
classed with obliterative counter shading. But the pattern of this part of a 
moth is evidently of scant importance, and accordingly tends to be scantily 
developed, compared with the upper-side pattern, and with the under-side 
patterns of perpendicularly-folding butterflies. 

There are, indeed, perpendicularly-folding moths, just as there are flatly 
applied butterflies, and the types of pattern are correspondingly interchanged. 

* (If there be such cases) — A. H. T. 
236 




139. Sphinx Moth (Philam^elus pandoims) on a birch trunk. 
Photoeraplied from life by Dr. 11. W. Shufeldt, 



But — especially in the moths' case — these are rare exceptions to a widely com- 
prehensive rule. On the other hand, moths' regular habit of flat-folding is sub- 
ject to several notable modifications. Many small kinds fold up almost cylin- 
drically, 'furling' their wings around their bodies, and when thus folded they 
sit fitted close to slender twigs or grass blades — ^like certain tree toads. Such 
moths often bear a mimetic likeness to bits of stick or grass, or even to bird- 
droppings, but often also they are patterned and colored ohliteratively. Again, 
the triangularly folded wings of many tree-bark moths, etc., slope downward 
steeply from the top ridge of the thick body, so that the moths' picture-patterned 
surface is by no means actually flat. 

Let us glance at a few more special types of pattern characteristic of ' close- 
lying' moths in general. Among all the various perches which these moths 
frequent, few or none are so abundantly favored by them as tree trunks. 
Accordingly, the tree-bark pattern, in various forms, is probably the most 
prevalent of all picture-patterns on moths' wings. The two extremes of this 
form of marking are: first, a pattern of the finest grizzling and speckling, 
which counterfeits with exquisite minuteness the look of finely broken bark, 
flecked with tiny lichens, etc. (see Figs. 136-138), and second, a pattern which 
depicts the larger details of rough or ragged bark, rendering, by contrasts of 
dark and light, by sharp lines and soft blendirigs, the look of sharp-edged 
substances casting shadows on their background. Each of these types, as is 
almost needless to say, is subject to multitudinous variations, and the two 
extremes are combined and intergraded to the last degree. A beautiful 
example of the larger-detail type, pure and simple, is the sphinx moth shown 
in Fig. 139. (See also Fig. 140.) But there are some still further specialized 
cases of bark-picturing among moths, sometimes accompanied by highly 
specialized habits. A large gray noctuid moth which I saw in the woods of 
Trinidad, B. W. I., always perched sideways on the trunks of trees and bushes. 
That is, it would sit with flatly-applied wings trending up and down the trunk 
instead of across it. Its flight was swift and straightforward, but in alighting 
it always whipped itself around into the sidewise posture. The reason, or at 

237 



least a most significant accompaniment, of this peculiar habit, was not far to 
seek. The 'secant' stripe, crossing the insect transversely from fore-wing 
tip to fore-wing tip (a type of marking very common among moths, whose 
patterns, like those of butterflies, are built on the simple basic laws of 'oblit- 
eration'), was on this kind specialized into a wonderfully sharp and vivid 
picture of a vertical bark-ridge. Such picturing of outstanding substance and 
cast shadow plays a large part in the disguisement of many animals of many 
classes, — nor is it, among moths, confined to those that perch on tree trunks. 
It reaches equally high and various development among the ground-perching 
kinds. These — the sylvan ones at least — tend to be brown (as the perchers 
on tree trunks tend to be gray). Their general scheme of color and pattern 
is much like that of the sylvan terrestrial butterflies, but they sit, for the most 
part, flatly applied, instead of perpendicularly folded, and therefore need 
still more direct and simple ground-picturing patterns. Sometimes, indeed, 
they present a resemblance hardly other than mimetic to single, brown, dead 
leaves. No doubt there are even full-blown brown-leaf mimics among 
them, as there are probably green-leaf mimics among those that perch on 
live foliage. But in the main, their coloration is obliterative, not mimetic — 
if anything, more patently so than the corresponding coloration of the bark- 
perchers. The leaf-strewn forest floor is more uneven, more studded with 
projections and pitted with depressions, than are tree trunks, and though a 
moth sits flatly outspread on it, his background tends to be less evenly and 
plainly near than is the bark moth's. And, though the ground moths' "cryp- 
tic" patterns contain less of the element of diverse-distance picturing than do 
those of the perpendicularly-folding butterflies which haunt like situations, 
the essential differences between the disguises of these two lepidopterous 
types are comparatively smaU, and sometimes quite in abeyance. Again, 
there is even close likeness between the patterns of some of these moths and 
that of certain terrestrial snakes, such as the Copperhead (Plate XI). Both 
picture dead, prostrate leaves, with their light, sharp edges and blurred shad- 
ows. For pure and subtile realism, the background-pictures worn by some 

238 



of these larger leaf -moths are hardly to be matched in any other branch of the 
animal kingdom. (See Fig. 133, B, B and C.) 

In the disguisement of butterflies and moths alike there is one seeming 
flaw, perhaps supported by insuperable organic limitations. That is, their 
usually perfect dual symmetry in all details of pattern.* The markings of the 
two wings on one side are as a rule almost exactly duplicated by those of the 
opposite pair; and such duality and repetition tends to attract the notice of 
the seeking eye. Of course it is only when the wings are outspread that this 
duality becomes in any degree a defect. Upfolded, a butterfly, though still 
dually symmetrical in fact, is not so in effect, any more than a bird or mammal 
is, for only one side can be seen at a time. Indeed, even when a moth or 
butterfly is outspread, its duality is usually frustrated in effect simply by the 
irregularity of its position relative to the eye. Birds, on the other hand, which 
tip and twist their heads, peeping and prying, with eyes in all sorts of irregular 
positions, must often see moths and butterflies symmetrical where we should 
not. Among moths this duality is often masked by sharp stripes which cross 
continuously the whole extent of the expanded or triangularly part-folded 
wings. Such a stripe, with its two sides unlike, 'cuts' the moth into two 
very unequal parts, dividing it across the direction of its dual symmetry, while 
the 'secant' itself pictures some landscape-detail — & stick or bark-ridge or 
leaf -stem, with a shadow on one side of it. Sometimes a marking of this kind 
cuts the fore-wings (or, more rarely, the hind wings) longitudinally, either 
crossing or skipping the intervening body; but as a rule it is diagonal, forming 
one clearly continuous (though not always straight) 'secant' stripe when the 
wings are folded in the normal resting-posture. There are many wearers 
and manifold variations of this marking, which, though often so very simple, 
is one of the most potent of the fundamentally 'obliterative' details of lepidop- 
terous pattern. 

It takes the eye of an artist, as we have said before, to recognize the wonder- 

* Of course, both sides of the insect need, in the long run, just the same pattern; while a score 
of circumstances tend to rescue it from betraying its actual duality. — A. H. T. 

239 



ful truthfulness of all these pictures which Nature paints. They are all — 
whether of bird, beast, fish, snake, or butterfly — not mere approximations, 
but essentially and typically true. (The reader must excuse the repetition 
of formulas and phrases calculated to bring home to him a vital but most 
subtile and illusive truth.) There is sense in the seeming paradox that a 
good caricature portrait of a man looks more like the man than he does him- 
self; and there is far more sense in the equally paradoxical sounding statement 
that the background-pictures worn by animals exceed their subjects in veri- 
similitude. For these pictures are not only somewhat caricatured, they are 
at the same time epitomized, compounded. Caricature of the average — a seeming 
contradiction in terms— is a phrase that fits the case. The salient and essential 
attributes of the pictured scenes have been slightly exaggerated, and cleared 
of all that is uncharacteristic. Many scenes have been merged into one, but 
all have yielded only what is typical and essential. A leaf is a leaf, and has 
nothing to lose by looking ordinarily leaf-like and no more, but a moth is 
not a leaf, and, if it is to profit by passing for one, it has much to gain by look- 
ing extraordinarily leaf-like— for so will the marauder's eye, seeking it as a 
moth, be the more surely balked from detecting it. Intensified qualities 
of pure leaf-like-ness of aspect no marauder will easily learn to associate with 
something which is wholly foreign to leaves in its real nature. 

All this being so, is it any wonder that artists should feel keen delight in 
looking at the disguising-patterns worn by animals? They are, in the best 
sense of the word, triumphs of art; and in a sense they are absolute, as human 
art can never be. He who would learn the surely typical color- and pattern- 
scheme of a particular kind or detail of natural landscape — tree-bark, leaf- 
strewn ground, or what-not — has only to look at the disguising-costume of the 
moth or snake or bird or butterfly which habitually has such a background. 
There he will find it in epitome, painted and perfected by Nature herself. 
Color and pattern, line and shading, — :all are true beyond the power of man to 
imitate, or even fully to discern. 



240 



APPENDIX A 

(Professor E. B. Poulton has kindly given us permission to append the follow- 
ing very remarkable addition to our subject.) 

[Extracts from] A few Notes on South African Chamaeleons, &c. By G. B. 
LoNGSTAFF, D.M., M.A., of New College, Oxford, and Edward B. 
Poulton, D.Sc, M.A., F.R.S., Hope Professor of Zoology in the Uni- 
versity of Oxford, and Fellow of Jesus College, Oxford.* 

The following observations were made during the visit of the British 
Association to South Africa in 1905. The conditions were not favourable to 
continuous investigation: nevertheless, I believe that some of these scattered 
notes are not without interest, especially those referring to the automatic 
adjustable countergrading of shadow on the two sides of the chamaeleon. It 
is probable that the independent control of the colours of the two sides of the 
body has been often observed before, but, so far as I am aware, this is the 
first attempt to explain the significance of the power. The illuminating 
effect of a great hypothesis like that of Mr. Abbott H. Thayer's in the realm 
of protective coloration is well seen in the fact that Dr. Longstaflf, Professor 
C. V. Boys, and the present writer independently grasped the meaning of the 
colour-change the moment it took place before their eyes. I do not know 
whether my two friends have studied Mr. Thayer's writings or examined his 
beautiful models at London, Oxford, or Cambridge,! but I have no doubt that 
it is the result of his work that interpretation was "in the air." 

I have to thank Mr. G. A. Boulenger, F.R.S., for kindly naming the 
specimens upon which the following observations were made. — E. B. P. 

* (Read 7th March, 1907.) [Printed in the Linneari Society's Journal — Zoology, Vol. XXX, 
October, 1907.] 

t [I was familiar with Mr. Thayer's models. — G. B. L., July 17, 1907.] 

241 



3. Note on Chameleon pumilus, Daudin, 9. By Dr. G. B. Longstaff. 

Taken on a shrub, about four feet from ground, in the Botanical Gardens, 
Cape Town, 9th August, 1905. 

Description. — Apple-green; at the back of the eye two patches of greyish- 
pink placed vertically; a lateral stripe of the same colour extending from 
shoulder to pelvis, widest in middle, where are two dark grey spots.. Several 
orange tubercles on the back. Belly striped with greenish white; underside 
of head striped blue-green and pink. The ground varies to dusky green. 

Kept in confinement. Observations on same made at Durban, i6th Aug., 
1905. After it had been kept for some time in the dark it became of the 
brightest apple-green. On exposure to light it darkened. Placed on a dark 
"uniform-case" near the window in bright light it darkened along the dorsal 
area. 

Taken out into the garden and placed alternately on a black pair of 
trowsers and on a white towel. It darkened in both cases, but there was no 
noticeable difference. Then put on a twig of a shrub with bright green 
leaves it became paler. The side away from the sun was of the brightest 
apple-green, the outer side (towards the sun) was darker along the hack. The 
bright green harmonized wonderfully with the young leaves, the creature 
appeared flat, and was scarcely distinguishable. The neck and belly did not 
appear to change colour. * * * 

4. By Professor E. B. Poulton. 

* * * Good fortune gave me as companions in the same compartment of 
the train two physicist friends, Captain Creak, F.R.S., and Professor C. V. 
Boys, F.R.S. One day, when C. pumilus was resting on the compartment 
table, with the long axis of its body parallel to the window, Professor Boys, 
who was certainly intended for a naturalist, pointed out that the strongly illumi- 
nated side, next to the window, was dark green, while the side in deep shadow, 

242 



away from the light, was of the brightest tint. The same relationship between 
the illuminated and the unilluminated side was seen on many occasions. 

This appears to be a most interesting adaptation — a dynamic manifestation 
— of the principle discovered in its static form by Mr. Abbott H. Thayer. Mr. 
Thayer first suggested that the relative shades of the dark back, lighter sides, 
and white under sides of animals were such as just to counterbalance the 
diminution of natural illumination from an open sky as we pass from the 
back down the sides to the under surface; that the object of this counter- 
grading was to neutralise the shadow which would otherwise render the 
animal conspicuous. C. pumilus, as I have said, manifests the same principle 
in a dynamic form. The side that happens to be turned away from the 
light is brightened sufficiently to neutralise the shadow; the high illumination 
of the other side is toned down by darkening, the effect being that all appear- 
ance of solidity is dissipated. This result must be of great importance to so 
large and so defenceless an animal as the chamseleon. But for this adjustable 
countergrading, the varying degrees of illumination on the side and dorsal 
slope turned towards the light, combined with the strong shadow on the other 
side, would cause it to stand out among the leaves as an object of conspicuous 
sohdity and thickness. 



243 



APPENDIX B 
ADDITIONAL NOTES BY A. H. THAYER 

CONSISTING OF OBSERVATIONS MADE TOO LATE TO BE EMBODIED IN 
THE TEXT OF THE BOOK 

During the progress of this book I have been discovering another 
beautiful fact about iridescence — one that vsras, of course, to be expected. 
The beautiful colors which compose it, and which leap into existence with 
the changing position of the wearer, or of the beholder, are evidently not 
mere general attempts at obliteration of the wearer, but are, each, so many 
perfect color-notes of that background which the changed situation demands. 

We have already shown that the peacock's neck is often leaf-green when 
looked down at, and pure blue sky-color when looked up at, so that it tends 
to fit itself exactly to each new background. It is now evident that other 
animals' iridescences are, like those of the peacock, repertories of exact back- 
ground colors. The gloss of the magpie's wing is at one moment a glimpse 
of sunlit evergreen, while the next instant it is the blue snow-shadow beyond 
the tree. In this way this very snow-picture, so perfectly achieved on the jays 
by dead color, is reached with equal precision on the magpie by one leap 
of iridescence. Throughout the world of brilliant animals, we find iri- 
descence playing this same part. The cormorant's green gloss in the water, 
looked up at from deeper down, proves to be a perfect match for the trans- 
lucent water itself. The crow's rainbow sheens, so little thought of as con- 
cealers, turn him into such true distance-colors as he sits on the nest, as to 
rank him at this moment almost with the grouse for . indistinguishability. 
(The nest itself, of course, has the disadvantage of attracting the eye, and 
thereby subjecting the occupant to a far keener scrutiny than the grouse 

244 



has to fear. Since crows are apparently too unappetizing,' as well as per- 
haps too formidable, to be much bothered by predatory animals, it would 
seem to be the eggs, and not the parents, that here most need protection.) 

What we know of the concealing-function of such costumes as that of the 
black-and-red South American Heliconii will bear further elucidating. 
These insects, in their abundance, and consequent general conspicuousness as 
a species, are on a par with our common yellow butterfly * here in the North. 
Both these species, existing in such immense numbers as to be almost con- 
stantly in sight, record, on the beholder's mind, one cumulative impression of 
conspicuousness. Yet each is colored for the utmost average concealment, 
at the very time when it most needs it — its feeding time. Such species are 
merely further proof of what our book demonstrates, viz.^ that Nature, in 
carrying out her principle of coloring animals for their most trying circum- 
stances, sometimes finds herself giving to a species that has one particularly 
dangerous habit, a coloration which, while it is the utmost imaginable con- 
cealer in the special situation it fits, looks necessarily more or less conspicuous 
and out of place everywhere else. 

These brilliant Heliconii, so magically concealed by their colors while they 
are feeding among red, yellow, or orange flowers, seem to be greatly indebted, 
during the rest of their day, to the protecting power of their habit of threading, 
with their rather slow flight, the interstices of dense foliage, where fly-catching 
birds have but a poor chance to capture them. In this habit of haunting the 
dense foliage, as well as in their colors, these Heliconii remind one of Scarlet 
Tanagers — a fact worthy of notice. 

There is no need of going to the tropics to study the concealing-power of 
the coloration of one of these red-and-black or yellow-and-black Heliconii. 
Place a dead one, or even an artificial one, on any kind of plant that has 
either red, yellow, or orange flowers, and not only will you find it wonderfully 
concealed, but you will perceive that the principle on which this concealment 
is achieved would always be operant wherever such a butterfly sat among 

such flowers. *Colyas. 

245 



One word more about Scarlet Tanagers. Their coloration, dividing them 
as it does into two things, a red thing and a black thing, is clear proof that con- 
spicuousness is not what is aimed at. Were these birds meant to be con- 
spicuous, they would, all the more because of inhabiting dense foliage, be 
monochrome. (The principle which underlies this fact is illustrated by the 
diagrams of letters in Plate V.) 

The rule seems to hold good that since animals must first of all breed, feed, 
and drink, their costumes will prove to be pictures of the scenes of these oper- 
ations. To speak here only of the feeding (the thing that occupies far the 
largest part, for instance of a male bird's time), there is among birds every 
degree of peculiarity of feeding-situation, from that of the hawk, which is 
the least peculiar — ^being wherever, in all outdoors, he gets a sufficiently good 
chance at a victim — to that of the macaw, which is one of the most peculiar 
and unvarying, commonly some tree-top full of luscious fruit, where he has 
merely to climb about a few feet to sate himself. What more powerful in- 
fluence toward dangerous relaxation of vigilance could be imagined? What 
wonder, then, since the macaw's banquet-hall is forever hung with one gor- 
geous tapestry of fruit and foliage scenes with sky-glimpses between, that his 
costume proves to be such as marvellously dissolves him into the scene, as he 
climbs about, burying his head in cluster after cluster of the brilliant fruit? 
This was just as much to be expected as that the hawk, whose feats take place 
now in one situation, now in another, should wear the very most generalized 
of concealment costumes. 

UPPER-SIDE WHITE PATCHES, ETC. 

It is perhaps possible to show still more clearly than we have yet pointed 
out the paramount function of upper-side white patches in general. 

In imitating, as we have shown that they do, sky-glimpses through inter- 
stices df the foliage-background, they pass off those parts of their wearer which 
they cover, for spaces, — more emphatically than spots of any other color could. 
The reason of this is that sky, the element which they represent, is the very 

246 . 



essence oj distance. All other colors seen amidst the foliage might represent 
one or another of its details, and any one of them occurring on an inhabitant 
helps to conceal him; but the finishing touch is given by his wearing, generally 
•on his very middle, this picture of sky, which, because sky of course is not in 
the wood at all, but immeasurably far beyond it, here represents no thing 
whatever, but an actual hole. When we say, "I can see daylight right through 
the place," we imply that there is nothing in that direction between our eyes 
and space. A white patch, then, in any such situation, whenever the light 
falls upon it sufRciently strongly, says clearly to the beholder, "There is 
nothing in this direction." No wonder that such a vast number of species 
that have sky glimpses in their foliage-background wear in their costumes 
this magical safeguard. Even in dark woods where white itself is much 
darkened, and where actual sky-glimpses are few, it is still the prerogative of 
these white patterns to represent, and more or less to match, the lightest, most 
illuminated and sky-like portions of the background. In general, the credit 
of white as an unmistakable glimpse of sky through the trees is so good 
that imitations of it easily profit by its name. There are often in sight a 
thousand real sky-vistas — how shall a hawk or other animal spend its energy 
in guarding against the occasional counterfeit! The fact undoubtedly is, 
that disguise, by all the means that we have pointed out, proves so successful 
as to discourage investigation, causing it to better repay predatory animals 
to watch merely for motion, and waste little effort in scrutiny of motionless 
details. 

Since the whole panorama of out-door objects is just one complexity of 
millions of outlines made by different-colored objects relieving one against 
another, each one showing against a more distant one, it follows that amidst 
this vast embroidery, a scrap of imitation of it must generally pass unnoticed, 
unless it takes the liberty 0} moving about! All the patterns and ornaments 
of the animal world are such scraps of imitation scenery, and their wearers 
are hunted both by man and by beast in the same way — viz., the watching 
with a relaxed eye as large a tract as possible for the least hint of motion. 

247 



Habitually to scrutinize the scene point by point would change an Accipiter's 
or a Flycatcher's life from a sufficiently easy to a most difficult one, such as 
would bring him near the starvation point, since he would necessarily bestow 
a large amount of his time in searching the wrong place, while his eyes no 
longer commanded the whole scene. The very position of Hawks' and Fly- 
catcher's eyes seems to prove all this to be true, since they face one eye to the 
left and one to the right, and therefore commonly regard two different scenes. 
No one can suppose that such a bird performs a feat of intellect beyond even 
a man's power, and acutely examines with focused eyes two points at once. 
An Owl's eyes, on the contrary, not constituting his stand-by sense, but needed 
at the grabbing-moment, face forward. Also, most interesting to record, the 
Hawk's eyes, not to be wanting in any service, turn forward, and assume 
the position of those of the Owl whenever the occasion demands. 

The fact that every pattern in the forest scene is caused by a thing of one 
color outlining against things of a different color beyond, makes it inevitable 
that similarly-coloTed notes on the coats of animals amidst the scene should 
receive a similar interpretation, and repeatedly pass off one or the other part 
of the wearer for something more distant than the rest of him, thus conceal- 
ing his existence. Hunters and collectors will find that these explanations 
show why they see so few of the inhabitants of the field or forest until they have 
once flushed them. Up to that moment each bright detail of these animals' 
costumes has commonly passed for a glimpse of something nearer or further 
than the thing represented by the rest of their colors. 

The longer one studies the subject of conceal ing-colors, the greater the part 
one discovers to be played by the intrinsic obliterative power of strongly con- 
trasting patterns. This principle is shown by Figs. 104-106 in our book, but 
should have received much more varied and elaborate illustration. We are 
forced, now, to leave the reader to make his own further illustrations. Let 
him cut out of very dark paper or cloth (cloth is best because is shows no light 
edge) some shape, — like, for instance, that of a butterfly, — and pin it, smooth 
and flat, upon a smooth expanse of cloth of some very slightly darker color. 

248 



Then, while he looks at this figure from nearly as far off as he can distinguish 
it from its background, let some one place a bit of bright white paper, likewise 
smooth and fiat, in the middle of the end part of one of the butterfly's wings. 
(The white spot should be about one third the wing's diameter.) The wing 
so treated, if it was very dimly distinguishable before, will now prove wholly 
invisible, in the vicinity of the white spot. This beautiful principle is of course 
a constant factor in the effect of all animals' patterns, — snakes, wasps, butter- 
flies, birds, etc. — and, in the sense that counter shading- merely prepares 
animals' bodies, as it were, to be painted upon, this other principle is almost the 
leading one of all. Such a butterfly as Heliconius amaryllis is a fine example. 
Against the dark of shadows that nearly match its own dark ground-color, 
its red spots 'obliterate' its adjacent outlines, and the sharp gold stripe that 
crosses the hind wings does the same for that part of the insect. The bright 
bar also illustrates the importance of the direction of such marks on animals. 
Being continuous (with very slight interruption) right across the insect's very 
body, it not only 'obliterates' it as a body, but, by its own cbnspicuousness, — 
in view of the fact that two things can't occupy the same space, — prevents one's 
suspecting the existence at that point of anything but a yellow grass-stem, or 
more often a sunlit twig, further off. 

Students once convinced of the real function of all such markings, will be 
delighted to discover the wonder-world they constitute. 

THE COOPERATION OF INTERPOSED VEGETATION WITH CONCEALING-COLORS 

Here is another fact of the greatest importance: Species that live amidst 
vegetation are looked at through a certain average amount of interposed joliage 
and twiggery. 

Let us imagine a man or other predatory animal stationed at some point 
in the forest. Obviously there is some limit to the distance to which he can 
see through the surrounding thicket, some point beyond which the last inter- 
stice is masked by leaves or branches. A little nearer than this limit begins 
the distance at which our observer can see, on an average, some small portion 

249 



of an object. Now from this point to the very space in which the observer 
stands there is a graded scale of the average amount of an object's surface which 
would at each particular distance be visible to hinj. We have learned from 
the diagrams in Plate V. that behind such a foliage lace-work any diversifi- 
cation of forest colors constitutes a costume more favorable to disguise 
than any monochrome. We have every reason to believe that these vegeta- 
tion-haunters wear designs absolutely adjusted to cooperation with this ever- 
present screen. 

While a naturalist is observing one Skunk, and conceiving its ruptive 
pattern a badge to advertise it, there are at the same moment (or there have 
been in the twilight and starlight of the previous night), thousands of other 
Skunks absolutely unrecognizable through the disruptive effect of their 
bleached-leaf-and shadow-colors seen through the interrupting tracery of 
forest under-growth, or of the rank vegetation of the prairie. 

ACKNOWLEDGMENTS, ETC. 

There are several men not mentioned in our book (written, mainly, several 
years ago) whom we should like to thank for generous furtherance, of one sort 
or another. Particularly, Alfred Russell Wallace, Sir E. Ray Lankester, and 
Mr. R. I. Pocock, in England, and Dr. C. Hart Merriam and Dr. J. A. Allen, 
in America. Mr. Pocock, furthermore, as shown by his various essays on 
protective coloration, has, independently, an unusually wide grasp on the 
whole subject. Had we seen his articles in time, they would of necessity have 
modified in some degree the exclusive tone of my Introduction, as well as my 
son's allusions here and there to the comparative apathy and blindness of 
naturalists in this matter. 

I take this opportunity also to correct, up to the limits of my present 
knowledge, several errors which appear in my earlier writings. One of these is 
my indorsement of Dr. C. Hart Merriam's theory about white rear-patches 
on deer, hares, etc. (Auk, Vol. XVII, No. 2, April, 1901.) Another is my 
avowed belief that there must somewhere be warning colors. (Transactions 

250 



of the Entomological Society of London, December 24, 1903.) This belief 
I no longer hold. Another is my statement, in the same article, that unshiny, 
bright monochrome constitutes intrinsically conspicuous coloration. Here I 
should have omitted the word bright. 

In the same paper, too, I wrote, by a slip of the mind, that animals 
have totally different sight from ours. On the contrary, everything that we 
know about this matter points to the opposite belief. What I was trying to 
say was simply that animals seem to have a different mental attitude toward 
their sight, since they appear to detect each other more exclusively than we 
do through perdeiving each other's motion. 

Lastly, in the same paper, I ascribed more importance to butterflies' resem- 
blance to flowers, as compared to their rendering of scenery, than I now 
should. A. H. Thayer. 

San Remo, Italy. 
December 28, 1908. 



LATER NOTES 

Our book having spoken of the Scarlet Tanager as often more conspicuous 
than dim-colored birds, while we clearly show the concealing-power of red 
patterns, I add here the clear distinction which I have at last perceived 
between the arrangement of this bird's red and that of every other species 
I have observed. It differs from that of the others in this respect: that while 
its contrast with the black of the wings and tail so far produces the usual 
ruptive effect, and thus, of course, lessens the bird's distinguishability, the 
red itself occupies continuously his whole head and body, right round him 
from top to bottom. 

This gives these parts the full conspicuousness of un-countershaded mono- 
chrome, and to the red itself it gives the peculiar brilliancy that any bright color 

251 



gains through grading out of shadow into light. This unmistakable conspicu- 
ousness of the most vital parts of this bird separates him from all the galli- 
naceous birds, from the large rail-class, from trogons, toucans, parrots, macaws, 
and a vast number of other species in whose costume brilliant scarlet patterns, 
often far larger than an entire tanager, perform demonstrably a totally obliter- 
ative part. Of this fact a few moments' experimenting with even stuffed 
specimens of the Red-and-yellow Macaw in a red-apple tree, or of the Quetzal 
in summer green- woods, will convince the most incredulous reader. In their 
cases, as in those of all the other red-patterned species that I have cited, a red 
pattern conceals its wearer in direct ratio to its own brilliancy. 

Our two Zebra photographs from Schillings, Figs. 88-89, ^^^ included 
in the book mainly to prove that Zebras do frequent reeds, etc., at their drinking 
times. Obviously, a nocturnal flashlight flaring against -their sides and light- 
ing so much more feebly the scene behind them, totally prevents their coalescing 
with it. The explanation of this disharmony, on page 136, is inadequate. 

New figures, one of them presenting the experiment suggested on pages 
248-249, have been substituted for the original 104, 105, and 106 of the first 
edition. A. H. T. 

MONADNOCK, N. H., 

April, 1 9 10. 



252 



INDEX 



Aard-vark, 126 

Ageronia. See Butterflies 
"Agouti, 119 

Ailuropus melanoleucus, 151 

Albatross, 75 

Alligator, 154, 176 

Amphibians, 178 

Anaconda. See Snake 

Angler, 167 

"Angle-wings." See Butterflies, Grapta 

Anhinga, 85 

Ant, 207 

Antbird, 113 

Ant-eater, Great Ant-eater, Little Ant-eater, 
Tamandua, 126, 149 

Antelope 

common, 142; harnessed, 142; koodoo, 
141 ; Livingstone's eland, 135, 142 ; prong- 
buck, figure 107, p. 154; figure 108, p. 154; 
figure 109, p. 154; figure no, p. 154. 

Ape, 122 

Aphides, 203 

Appendages 

crests, note in legend over frontispiece, 
obliterative function of, 9, 12, 95; of 
butterflies, 224, 230; of moths, 233; pan- 
taloons (leg-feathers), 84; plum.es, 98, 
see legend of Plate VI, opp. p. 107; tails, 
95, 108, 233; wattles, 85; wings, 224, 225, 
230 

Armadillo, 125 

Axolotl, 181 

B 

Background-picturing Patterns 

compounding of, 36; intermingling of 
types of, 54; perspective of, 31, 139, 217, 
235; realism of, 3^, 240; underlying prin- 
ciples of obliterative effects of, 30-32, 36, 
226-232, 249 

Bark Type 
beetles, 201; butterflies, 216; cicada, 202; 
lizards, 175; moths, 237; spiders, 210; 
toads, 179, 180; woodpecker, 50; wry- 
neck, 50 

Bottom Type 

cod, 170; ducks, 63 ; painted tortoise, 178; 
seals, 170; trout, 170 



Background-picturing Patterns — Continued 

Forest-crown Type 

bird of paradise, 109; bluebird, io8;indigo 
bunting, 108; jacamar, 109; macaw, 109; 
motmot, 109; parrot, 108; tanager, 109; 
toucan, 109 

Forest-vista Type 

Calligo eurylochus, 217; European eagle 
owl, 41 ; great gray (and lapj)) owl, 41 ; 
great homed owl, 41; hazel grouse, 38; 
ruffed grouse, 38, 39, 40; screech owl, 41 ; 
European woodcock, 42 

Grass Type 

bittern, 56; curlew, 53; great bustard, 48; 
frogs, 46, 180; jaegers, 75; larks, 45; 
little bustard, 48; moths, 46, 235; pecto- 
ral sandpiper, 53; pipits, 43; ptarmigan, 
45, 46; thickknees, 53; tiger heron, 57; 
tinamous, 48 ; warblers, 45 

Ground Type 

Calligo butterflies, 218 ; copperhead snake, 
156, 174; frogs, 178; goatsucker, 35, 156; 
Kamchatkan sea-eagle, 152; larks, 44; 
locusts, 198; moths, 238; nighthawks, 
54, 198; pipit, 45 ; quail, 45; rattlesnake, 
174; skunks, 151; snipe, 33, 34, 156; 
sparrow, 45; toads, 181; Thibetan snow 
bear, 152; warblers, 45; woodcock, 33, 

34 

Heather Type 

plover, 53 ; Scotch grouse (Ptarmigan), 47 

Leaf Type 

caterpillars, 186-194 

Reed Type 

antelopes, 141, 142; bittern, 57; herons, 
57; zebras, 135-139 

Ripple Type 

ducks, 62, 92; green heron, 92 

Rock Type 

butterflies, 216; cormorants, 65; fishes, 
165; nighthawk, 54, 165; purple sand- 
piper, 54; seals, 170; spiders, 210 

Sand Type 

crabs, 165; curlew, 53; flounders, 164; 
knot, 53; locusts, 198; plaice, 164; puff 
adder, 175, 198; sanderling, 53; semi- 
palmated sandpiper, 53 ; stint, 53 ; thick 
knees, 53 

Shadow Type 

spiders, 210; squirrels, 143, i44;tiger, 140; 
zebras, 135-138 



253 



Background-picturing Patterns — Continued 
Sky Type 

albatross, 75; ant-eaters, 149; antelopes 
153; bald eagle, 74; black lark bunting 
157; bobolink, 157; cranes, 154; deer, 152; 
egrets, 118, 155; elands, 142; flamingoes, 
154; fulmars,7s ■,gannets,75; gulls,74,i54; 
hares, 1 52; herons, 74, n8, 154, 155; ibises, 
154; Kamchatkan sea-eagle, 152; larks, 
157; longspurs, 157; moths, 234; osprey, 
74; ratels, 149; skunks, 148, 151; snowy 
owl, 73, 114, 117, 154; spilogale, 150; 
spoonbills, 154; storks, 154; swans, 118, 
iS4;Tasmaniandevil, 149; terns, 154; Thi- 
betan snow bear, 152; tropic birds, 75; 
white gerfalcon, 114, 154; wolverine, 149; 
wood duck, 66, 67, 69; zebras, 138; zoril, 

150 
Sun-fleck Type 

boa, 13s, 175; butterflies, 220, 221; deer, 
I45;girafi[e, 133, 134; jaguar, i33;leopard, 
133, 134; mammals, 144; ocelot, 135, 175; 
ounce, 135; python, 175; serval, 135; 
spiders, 210; wild swine, 145 
Water Type 

ant-birds, 113; chevrotain, 143; courlan, 
61; dragon-flies, 209; ducks, 62, 63; 
harnessed antelopes, 142; herons, 58; 
jacanas, 59; lape, 143; purple gallinule, 
59 ; rails, 61; seals, 170; wood sandpipers, 
61 
Winter-landscape Type 

blue jay, 114, 115; crossbills, 116, 117; 
goshawk, 116; linnets, 116, 117; nut- 
hatches, lis, 116; pine grosbeaks, 116, 
117; ptarmigans, 113; snow bunting, 116; 
snowy owl, 114; titmice, 114, 115; white 
gerfalcon, 114; woodpeckers, 114, 115 

Badger, 148 - 

"Banner marks,'' 5 

Bark Patterns. See Background-picturing 
Patterns 

Bat, 119, 120 

Bates, English naturalist, quoted, 224 

Beak, 70, 85, 86 

Bear, 123, 124, 152 

" Beauty-spots " of hummingbirds, 103, 104 

Beaver, iig, 122, 130 

Beebe, C. W., on the disguising coloration of 
Heliconius charitonia, 221 

Beetle, 200 

Bill. See Beak 

Bird of paradise, 97, 98, 109, see Plate VI, opp. 
p. 107 

Birds • 

aquatic, 59 seq.; arctic, 113 seq.\ ground, 
33 seq., 44 seq.\ ocean, 72, 73; scansorial, 
49 seq.\ shore, 52 seq.; swamp, 56 seq.\ 
tree-perching, 38 seq.; tropical, 107 seq. 

Bittern 

American, 56, 100, figure 53, p. 58; Eu- 
ropean, 57; least, 57 



Blackbird 

European, 27; red- winged, 86 note 

Bluebird, 108 

Bobolink, 157 

Bob-white, figure 50, p. 48 

Borer, 205 

Bottom Patterns. See Background-picturing 
Patterns 

Bunting 

black lark, 157; indigo, 91, 108; snow, 
116, 151 

Bustard, 48 

Butterflies 

aerial class of, 219-226; dazzling colora- 
tion of, 224-232; disproportionately large 
wings of, 230; mimicry of, 214, 215, 228; 
ocelli of, 229; sedentary class of, 219—226; 
symmetry of wings of, 239; wing-waving 
of, 219, 245; figures 56-57. -P- 78; figure 
106, and figures 128—133. 
Ageronia, 234; Calligo, 229; Euchlm carda- 
mines, 216; Grapta, 232; Hetcera esmeralda, 
224; Heliconii, So. American, 245; Heli- 
conius amaryllis, 249; Heliconius chari- 
tonia, 221, 223; Heliconius melpomene 
214, 215, 216; Heliconius sara, 223; hum- 
mingbird papilio, 223; Hypolymnas mi- 
sippus, 221; Kallima tnachis, 4, 214, 216; 
Lycorea atergatis, 223; Mechanitis verita- 
bilis, 223; Metamorpha dido, 216, 222; 
Morpho anaxibia, 225; Nymphalis bolina, 
221; Papilio gargasus, 223; Papilio poly- 
damas, 220; Papilionidce, swallow-tailed, 
232; Pierince, 228; Satyrince, 220; Tithorea 
megara, 223; Vanessa, 232 

Buzzard, rough-legged, 84 



Caddis, 209 

Calligo. See Butterflies 

Camelopard. See Giraffe 

Cape Polecat. See Zoril 

Capybara, 130 

Cat, 4 

Catbird, 27 

Caterpillar 

see Plate XII, opp. p. 183; Plate XIII, 
opp. p. 188; Plate XIV, opp. p. 192; Plate 
XV, opp. p. 194; and Plate XVI, opp. p. 
196; background-picturing of, 191-193; 
co-operation of mimicry and counter-shad- 
ing of , 188-igi; mimicry of, 193-197; 
obliterative shading of, 185 seq. 

Chafer, American Rose, 201 

Chameleon, dynamic counter-shading of, 242, 

243 
Chameleonism 

of chameleons, 242, 243; of fish, 168; of 
frogs, 180, i8i; of lizards, 175; of toads, 
179 



254 



Chapman, F. M., on the birds of Trinidad, 1 1 1 
seq. 

Cheetah, 153 

Chevrotain, African Water, 143 

Chickadee, figure 61, p. 78 

Chipmunk, 143, figure 13, p. 28, and figure 93, 
p. 138 

Cicada, Dogday, 202 

Civet, 119 

Cockroach, 200 

Cod, 170 

Color 

of desert animals, 127 ; of female birds, 39, 
70, 78, 106, 117, 145, 14^; secondary part 
of, in animal distinguishability, 17 
Bright 

concealing effect of, 4, 19 and note, 86 
note, 87-94, 104, 222; of bills and feet of 
birds, 85, 86; dimmed by foliage-reflec- 
tion, in; of amphibians, 182; fishes, 165, 
166, 168; hummingbirds, I04;lizards, 172; 
northern birds, 116; painted tortoise, 177; 
trogons, in; scarlet tanager, in; snakes, 
172 
Changeable 
kinds of, among birds, 91; "window- 
opening' effect of, 93 
Complementary 

in tropical bird costume, no, in 
"Cryptic," n, 212, 214, 234 

See also Iridescence and Chameleonism 

Conepatl. See Skunk 

Coot, 59, 61 

Cormorant, 65, 244 

Cougar, 3, 153 

Counter-shading 

distinguished from obliterative coloration, 
25; experimental demonstrations of po- 
tency of, 20, 25, 140, 186, 187; inverted, 
124, 147-150, 186, 211; law of, 27; solidity- 
effacing effect of, 14-16 

See also Obliterative Coloration 

Courlan, 61 

Crab, aquatic, 165; sand, 156; spirit, 165 

"Creaker." See Butterflies, Ageronia 

Creeper, wood, 49, 115 

Cricket, 200 

Crocodile, 176 

Crossbill, 116, 117 

Crow, 244 

Curlew, 45, 53, figure 76, p. 82 

D 

Darwin,. Charles, n, 12, 16 

Dazzling Marks. See Markings 

Deer, flight-masks of, 152, 153; obliterative 

markings of young of, 145 
Desert, coloration of animals of, 26 
Dewdrop Patterns. See Patterns 
Disguise, importance of slight advantages of, 

6, 7, 88 



Distractive marks. See Markings 

Dog, 4. 119 

Dolphin, 119 

Dragon-fly, 207, 209 

Duck 

eider, 62, 65, 79, figure 47, p. 46; gar- 
ganey, 62; golden-eyes, 62; harlequin, ^8; 
fong-tailed, 62; mallard, 89; mandarin, 
71; merganser, 62, figure 78, p. 82, and 
figure 79, p. 82; old squaw, 62; pintail, 
62; ruddy, 64; scaup, 64; scoter, 65; teal, 
62; widgeon, 62; wood, 62, 66-71, 92, 130, 
177, see Plate III, opp. p. 59, and Plate 
IV, opp. p. 70 

Duck-billed platypus, 122 

Dugmore, A. R., quoted, 168 

Dugong, 123 

E 
Eagle, 74, 152 
Earwig, 200 
Echidna, 121 

Eckstorm, Mrs. F. H., 19 note 
Eclipsable Markings. See Markings 
Egret, 58, 155, figure 116, p. 156; figure 117, p. 

156; figure 118, p. 156; and figure 118 A, 

P- 156 
Eider. See Duck 
Eland. See Antelope 
Elephant, 119 
Ephemera, 209 

Euchlce cardamines . See Butterflies 
Eyes, masking of, 81, 82 and note 



Feathers, in the composition of patterns, 139 

Female, sexual differences in costumes of, 27, 
39, 60, 65, 70, 71, 78, 105, 106, 117, 145 

Ferret, 4 

Fish, 1 60-1 7 1 

Fisher. See Martin 

Fish Hawk. See Hawk, Osprey 

Flamingo, see Plate IX, p. 156, and Plate X, 
p. 156, and legend; "showy" costumes 
of, 154 

Flight masks, 152, 153 

Flight Patterns. See Patterns 

Flounder, 164 

Flower Patterns. See Patterns 

Fly, 206 

Forest Background Patterns. See Back- 
ground-picturing Patterns 

Fox, 3, 7, 119, 151, 152 

Frog, 46, 85, 156, 167, 169, 178, figures 125-126, 
p. 180 



Gadow's marks, 5 
Galadictis, striata, viitata, 147 
Gallinule, 59-61, 91, 130 



255 



Gannet, 155 

Garganey. See Duck 

Gerfalcon, white, 114, 152 

Gila monster, 174 

Giraffe, 132-134 

Glutton. See Wolverine 

Gnat, 207 

Goatsucker 

mimicry of, 10 1; minute patterns of, 35, 
39; young of, 82 

Golden Eye. See Duck 

Gopher, 127 

Grampus, 123 

Grapta. See Butterflies 

Grasshopper, 199, 200 

Grass Patterns. See Background-picturing 
Patterns 

Grebe, 83, figure 77, p. 82, and figure 80, p. 82 

"Green Page." See Moths, Urania 

Grosbeak, 116, figure 13, p. 28 

Ground Patterns. See Background-Picturing 
Patterns 

Grouse 

figure 31, p. 37; figure 32, p. 37; figure 33, 
p. 40 ; figures 34-3 5 , p. 40 ; figure 43 , p. 44 ; 
figure 44, p. 46, and figure 45, p. 46 ; hazel, 
38; ruffed, 38, 39, 40, 69, 100, loi, 156, 
217, see Plate II, opp. p. 38; Scotch, 45; 
young of, 82 

Guillemots, figure 63, p. 78 

Gull 

coloration of, 72; black-head, 74; jaegers 
(robber), 75; laughing, 74; young of, 74, 
75, figure 75, p. 82 



H 



Hairs, in the composition of patterns, 139 

Hare, 7, 119, figure 85, p. 128; figure 86, p. 128; 
figure 103, p. 150; figure 112, p. 154; and 
figure 113, p. 154 

Harlequin. See Duck 

Hawk 

figure 13, p. 28; prey-bewildering mark- 
ings of, 80; wing area of, 231; goshawk, 
80, 116, figure 64, p. 80; figure 65, p. 80; 
and figure 66, p. 80 ; harpy 84; osprey, 74, 
85; red-tailed, 231 

Heather Patterns. See Background-picturing 
Patterns 

Hedgehog, 119, 121 

Heliconii. See Butterflies 

Hen, 25, figure 6, p. 26 

Heron 

coloration of, 58; colored beaks of, 85; 
habits of, 56; great blue, 74; green, 92; 
purple, 57; tiger, 57; white, 155 

Hetaera esmeralda. See Butterflies 

Hiding Patterns. See Patterns 

Hippopotamus, iig 

Hole-picturing. See Patterns 



Hopper 

leaf, 204; tree, 202 
Hornet, 205 
Hornpout, 169 

Hummingbird Papilio. See Butterflies 
Hummingbirds ' 

coloration of females, 105; function of 

flashing headgear of, 105 note; oblitera- 

tive equipment of, 103-106 
Hunting Frog. See Angler 
Hyena, 119 

Hypolymnas misippus. See Butterflies 
Hyrax, 119 



Ibis, J 54 

Iguana, 174 

Inchworm, 4 

Indistinguishability, conditions of , 7, 9-1 1, 13 

Iridescence 

potency of in animal concealment, 87-89, 
94, 95, 244, 24s; of butterflies, 224; of 
dragon-flies, 208; of fishes, 167; of flies, 
206; of herons, 58; of humming-birds, 103 

J 
Jacamar, 90, 109, 206 
Jacana 

colored wattles of, 85; habits of, 59; 

obliterative shading in young of, 60 ; 

spurs of, 60, 61 
Jackal, 127 

Jaguar, 132, 133, 134, figure 87, p. 132 
Japanese, animal pictures of, 28 note 
Jay, blue, 114, 115, see Plate VI, opp. p. 107; 
figure 13, p. 28, and figure 60, p. 78 

K 

Kallima inachis. See Butterflies 

Kangaroo, 132 

Katydid, 199 

Kingfisher 

changeable coloration of, 90, 91; dazzling 
markings of, 155; habits of, 130; com- 
mon European, 91 

Kipling, Rudyard, quoted, 135 note 

Knot, 53 

Koodoo. See Antelope 



Lape (Paca), 143 

Lapwing, figure 6g, p. 81 

Lark, 44> i57 

Leaf -disease-spots, mimicry of by caterpillars, 
189 

Leaf insect, 198 

Leaf Patterns. See Background-picturing Pat- 
terns 

Leaf -vein Patterns. See Patterns 



256 



lieg-feathers. See Appendages (pantaloons) 

Lemming, 144 

Lemur, 144 

Leopard, melanism of, 133 ; pattern of, 134, 

figure 17, p. 30 
Linnet, redpoll, 106, 116 
Lion, 132, 13s, 137, IS3 
Lizard, 172, 174, 175, 233, figure 124, p. 180 
Locust, 198, 200 
Longspur, 157 
Longstaff, G. B., note by, on South African 

chameleons, 242 
Long-tailed Duck. See Duck 
Lustrousness, importance of, as a factor of 

obliterative coloration, 148, 226 
Lycorea atergatis. See Butterflies 
Lynx, 7, iig 

M 

Macaw, 109, 246 

Magpie, 115, 244 

Mallard. See Duck 

Mammals 

absence of bright coloring in, 130; ar- 
boreal, coloration of, 129; disguising 
coloration of, 119 seq. 

Mandarin. See Duck 

Manatee, 123 

Mantis, 198 

Mantispian, 209 

Marbling. See Markings 

Markings 

axiom of, 80; concealing principles of, 77- 
80, 95, 96 
Dazzling (Distractive) 

principles of, 151, 152, 246, 247; of but- 
terflies„2i9, 225, 227, 233; gulls, 74; hum- 
ming birds, 104, 105; Kamchatkan sea- 
eagle, 152; locusts, 199; moths, 233; 
plunging fishing-birds, 155; ptarmigans, 
152; skunks, 151; snowy owl, 151, 152; 
terns, 74; Thibetan snow bear, 152; wea- 
sels, 152; white gerfalcon, 151, 152 
Eclipsable 

of butterflies, 227; of deer, 153 
Eye-masking, 81 and note, 82 
Marbling, 70 
Ocelli 

disguising effect of, 229, 230, legend of 
Frontispiece, figure 132, p. 230 
Speculum 

effect of iridescence of, in the Mallard, p. 89 
function of, in disguise of ducks, 64 
Stripes, lengthwise 

concealing principle of, 95, 96; of birds, 
95, 96; caterpillars, 195; snakes, 10,96, 
174 
Stripes, transverse 

concealing principle of, 95, 96 ; of antelope, 
135, 141 {beetles, 201; hawks, 80; iguanas, 
174; lizards, 174; Myrmecobius fasciatus. 



Markings — Continued 

Stripes, transverse — Continued 

141 ; owls, 80 ; pheasants, 95, 97 ; quaggas, 
141; snakes, 10, 96, 97, 174; tigers, 140; 
zebras, 135 
"Target," 97, 182 

Marmoset, 144 

Martin, Pennant's (Fisher), 123 

Meadow lark, figure 46, p. 46 

Mechanitis veritabilis. See Butterflies 

Melanism, of the leopard and jaguar, 133, 134 

Merganser. See Duck 

Merriam, Dr. C. H., 250 

Metamorpha Dido. See Butterflies 

Mimicry 

approach of obliterative coloration to, 36 ; 
"Batesian and Mullerian" groups, 223; 
color and pattern, 195; compound, 184, 
216; cooperation of, with obliterative 
shading, 188; definition of, 24 and note; 
distinguished from obhterative colora- 
tion, 100, loi, 103; structural, 193, 194; 
of butterflies, 4, 214, 215, 224, 228; cater- 
pillars, 4, 183-197; crocodilians, 176; 
dragon-flies, 208; fishes, 167; grass-snake, 
173; moths, 4, 236; red crossbills, 117; 
sloth, 124; spiders, 210; toads, 179; tree 
hopper, 203 ; woodland goatsucker, loi 
See also Patterns 

Mink, 28, 153, figure 13, p. 28 

Mole, 119, 122 

Mongoose, 119 

Monkey, 122, figure 04, p. 146 

Morpho anaxibta. See Butterflies 

Mosquito, 207 

Moth 

dual symmetry of wings of, 239; oblitera- 
tive and disguising costumes of, 232-239; 
bark, figure 136, p. 235 ; figure 137, p. 235 ; 
and flgure 138, p. 235; cecropia, 186; Cyn- 
thia, figure 133, p. 230; grass, figure 134, 
p. 23s; hawk (Sphingidce),, 236; imperial 
walnut, 187, 188 note; luna, 185, 186, 232 ; 
polyphemus, 185; promethea, 186, figure 
133. P- 230; sphinx, 125, 237, figure 139, 
p. 237, and figure 140, p. 237; tiger, figure 

„ I3S.P- 23S;urania, 232, 233 

Motmot, 109 

Mouse, 119; jumping, figure 13, p. 28 

Mud-puppy, 181 

Mud-turtle. See Tortoise (painted) 

Muskrat, 130, figure 13, p. 28 

Myrmecobius fasciatus, 141 

N 

Natural Selection 

influence of in balance between predators 
and prey, 88, 89; protective coloration a 
result of , 5, IS, 36 note, 88, 151 

Nestlings, protective coloration of, 82, 83 

Newt, 181, 233 



257 



Nighthawk, 54, 198, figure 29, p. 36; figure 30, 
p. 36; figure 73, p. 82; and figure 74, p. 
82 

"Nuptial dress," erroneous theory of, 4, 5 

Nuthatch, 49, 78, 115, 116 

Nymphalis bolina. See Butterflies 

O 

Obliterative Coloration 

animals which form exceptions to general 
rule of, 126; combined with background- 
picturing in birds, 33-71; cooperation of 
markings with, 30-32 ; erroneous theory of, 
28; experimental demonstration of, 136; 
inversion of, 124, 147; law of, 27; per- 
fection of, in butterflies, 231; principles 
of, 14-21 ; unaccompanied by obliterative 
shading, 196 
See also Counter-Shading and Irides- 
cence 

Ocellus. See Markings 

Ocelot, 132, 17s 

Old Squaw. See Duck 

Opossum, 119 

Optical illusion, the basis of protective color- 
ation, 3 

Orang-outan, 122 

Ornithorhynchus paradoxus, 122 

Otter, 119, 130 

Ounce, 13S, 141 

Outline concealment, natural devices for ac- 
complishment of, in animals, 95 seq., 
227 

Owl 

American great horned, 41, figure 36, p. 
41; European eagle, 41; great gfay, 41; 
lapp, 41; long-eared, figure 37, p. 42, and 
figure 38, p. 42; short-eared, figure 48, 
p. 46; screech, 41, 42, 100; snowy, 114, 
iSi> 152 

Owl Butterfly. See Butterfly, Calligo eury- 
lochus 

Oyster-catcher, 27, figure 62, p. 78 



Paca. See Lape 

Pangolin, 125 

Pantaloons (leg-feathers). See Appendages 

Papilionidce. See Butterflies 

Parrakeet, 27 

Parrot, 27, 108, 167 

Partridge, 13 

Patterns 

axiom of, 80; obliterative principles of, 
9, 77-80; background picture, see Back- 
ground-picturing Patterns 
Dewdrop 

butterflies, 229, 230; spiders, 210 
Flight 

of butterflies, 222-224; of moths, 233 



Patterns — ConUnued 

Flower 

of butterflies, 216, 220, 228, figure 128, p. 
216, figure 129, p. 216; humming-birds, 
103; spiders, 210 

Hiding 

of butterflies, 216, 217, 219, 225 ; of locusts, 
199; of moths, 225 

Hole-picturing 

of caterpillars, 195; leopards, 133; owls, 
iS8;raccoon, is7;sloth, 1 2 5 , sphinx-moth 
larva, 125; spiders, 211; whip-poor-will, 
158, figure 131, p. 216 

Leaf vein 

of caterpillars, 185 

Ruptive 

concealing principles of, 77, 78, 79, no; 
of ant-eaters, 126; bees, 205; beetles, 201 ; 
butterflies, 228; ducks, 65, 78; gannets, 
155; grasshoppers, 199; kingffishers, 155; 
locusts, 198; magpies, 115; moths, 236; 
nuthatches, 115; ospreys, 155; pelicans, 
155; plover, 79; prongbucks, 145; quail, 
79; skunks, 123, 1 5 1 ; tanagers, in; tit- 
mice, lis; trogons, no, in; wolverines, 
123 

Secant 

concealing principles of, 77, 78; of am- 
phibians, 182; ant-eaters, 126; batrachi- 
ans, 181; ducks, 78; frogs, 78; harnessed 
antelope, 143; Hymenoptera, 204, 205; 
koodoo, 142; Livingstone's eland, 142; 
maekerel, 162; moths, 236, 239; sparrows, 
78; squirrels, 143; toads, 78; zebras, 138, 

139. 143 
Variable 

ptarmigans, 45 
See also Markings 

Peacock 

See Frontispiece; concealing effect of tail 
of, 9S, and legend of Frontispiece; obliter- 
ative iridescence of, 88, 244 

Pelican, 155 

Perspective, of animal patterns. See Back- 
ground-picturing Patterns 

Petrel, 75 

Phalanger, 119 

Pheasants 

concealing effect of tails of, 95, 97, figure 
133, p. 230; ocelli of, 229 

PierincB. See Butterflies 

Pigmentation in caterpillars, 187 notes 

Pintail. See Duck 

Pipe-fish, 167 

Pipit, 45 

Plaice, 164 

Plant Lice. See Aphides 

Plover, 52, 53, 79, figure SI, p. 48; figure S2, p. 
48 ; figure 67, p. 81 ; figure 68, p. 81 ; figure 
70, p. 82; figure 71, p. 82; and figure 72, 
p. 82 

Polliwog, 169 



258 



"Poor-me-one." See Goatsucker 

Porcupine, 119, 121 

Porpoise, 119 

Poulton, Prof. Edward B. 

extract from article by, 2 1 ; note by, on 
South African chanieleons, 241 

Prairie Skunk. See Conepatl 

Predators, balance between prey and, 7, 88 

Prey, balance between predators and, 7, 88 

Prongbuck, American, 145 

Protective Coloration 

basis of, 3; definition of,. 24; erroneous 
conception of, 4, 13 ; importance of slight 
advantages of, in animal disguise, 4, 6, 7, 
88; similarity of, in species of similar hab- 
its, s; underlying law of, 13-23. See also 
Background-picturing Patterns, Counter- 
shading, Markings, Mimicry, Obliterative 
Coloration, and Patterns 

Protective resemblance, 24 note, 100 

Ptarmigan 

see figure 8, p. 26; figure 9, p. 26; figure 
10, p. 26; figure 39, p. 44; figure 40, p. 44; . 
figure 41, p. 44; and figure 43, p. 44; daz- 
zling marks of, 152 ; variable coloration of, 
45, 47, 113 ; winter plumage of, 113 

Python, 17s 

.Q 

Quagga, 138 
Quail, 45. 79 
Quetzal (Resplendent Trogon), 95 

R 

Rabbit, cottontail, 127, see Plate VII, opp. p. 

119, figure 12, p. 28, and figure 84, p. 

128 
Raccoon, 119, 157 
Rail, 61, figure 54, p. 58 
Rat, iig 
Ratel, 149 
Rattlesnake, 174 
Reed Patterns. See Background-picturing 

Patterns 
Reptiles, obliterative shading of, 172 seq. 
Rhinoceros, iig 

Ridgeway, Robert, quoted, 54 note 
Ripple Patterns. See Background-picturing 

Patterns 
Rock Patterns. See Background-picturing 

Patterns 
Ruddy Duck. See Duck 
Ruptive Patterns. See Patterns 



Salamander, i6g, 181, 182 

Sandpiper, 27, Sf, 53. 54. 61 

SatyrincB. See Butterflies 

Sawfly, 205 

Scaup. See Duck 

Scent of animals, 3, 81 note, 137 note 

Scorpion fly, 209 

Scoter. See Duck 

Sea-cow. See Manatee 

Sea lion, 119 

Seal, 170, see figure n. P- 28 

Secant Patterns. See Patterns 

Serval, J35 

"Sexually selected colors," erroneous theory 
of, 5, 6 

Shadow-picturing Patterns. See Background- 
picturing Patterns 

Shark, 154, 163 

Shearwater, 75 

Shore birds, obliterative patterns of, 52 

Shrew, 119, 122, figure 13, p. 28 

Sight of animals, 3, 81 note, 137 note, 164 

Siren, 181 

Siskin, figure 13, p. 28 

Skunk, 123, 148, 149, 15s, 250, figures 95-103, 
pp. 148-150 

Skunk-blackbird. See Bobolink 

Sky Patterns. See Background-picturing Pat- 
terns 

Sloth, mimicry of, 124, 125, 157 

Snake 

anaconda, 154; boa; 132, 175; coral, 10; 
copperhead, 82, 156, 174, 238, see Plate 
XI, opp. p. 172; grass, 173; green, figures 
121-122, p. 174; puff adder, 175; py-thon, 
17s; rattle, 174, figure 123, p. 174 

Snipe, 33, 54, figure 25, p. 34, and figure 26, p. 

34 
Snow Leopard. See Ounce 
Sparrow, 45, 78 
Speculum. See Markings 
Spermophile, 143, 144 
Spider, 210 seq., figure 127, p. 180 
Spilogale, 150 
Spoonbill, roseate, 154, see Plate VIII, opp. 

p. 147 and Plate IX, opp. p. 156 
Squash bug, 202 

.Squirrel, 27, 119, 143, 144, figure 13, p. 28 
Stevenson, R. L., quoted, 6 
Stilt, 27 
Stint, 53 

Stripes. See Markings 
Sunrfleck Patterns. See Background-picturing 

Patterns 
Swallow, figure 13, p. 28 
Swan, 65 



Salmon, 162 
Sanderling, 53 
Sand Patterns. 
Patterns 



See Background-picturing 



Tadpole, i6g 

Tail. See Appendages 

Tamandua. See Ant-Eater 



259 



Tanager, ig note, 109, iii, 245, 246 

"Target" Markings. See Markings 

Tasmanian Devil, 149 

Teal. See Duck 

Teledu, 147, 148, 149 

Tern 

figure 55, p. 58, oceanic coloration of, 
72; prey-confusing markings of, 155 

Thickknee, 53 

Thylacine. See Wolf, Tasmanian 

Tiger, 135, 140, 141 

Tinamous, 48 

Tithorea megara. See Butterflies 

Titmouse, 114, 115 

Toad 

chameleonism of, 179; patterns of, 156, 
180, 181; green, 181 note; ground, 181; 
natterjack, 181 note; tree, 179, 180; 
young of, 169 

Tortoise, 176, 177 

Toucan, log, 167 

Tree-hopper, 202 

Trogon 

concealing tails of, 95; complementary 
coloring of, no; inconspicuousness of, in 

Trout, bottom-picturing patterns of, 169, 170; 
chameleonism of, 169 

Turkey, 88 

Turtle, 177 

V 

Vanessa. See Butterflies 
Variable Patterns. See Patterns 



W 

Wagtail, figure 49, p. 48 

Walking stick, 198 

Wallace, A. R., 11, 12, 150 

Walrus, 119 

"Warning colors," 5 

Warblers 

chestnut-sided, figure 58, p. 78; figure 59, 
p. 78; European, 45; wood, 79 



Wasp, 205 

Water boatman, 204 

Water Patterns. See Background-picturing 

Patterns 
Wattle. See Appendages 
Weasel, 4, 119, 151, 152 
Whale, 119, 122, 123 note 
Whip-poor-will, 158, figure 27, p. 35, and figure 

.28. P- 3S 
Whitethroat, figure 13, p. 28 
Widgeon. See Duck 
'Window opening,' effect of changeable colors, 

93 

Wings 

comparative area of, in birds and butter- 
flies, 231; waving of, by butterflies, 219 
See also Appendages 

Winter Landscape Patterns. See Background- 
picturing Patterns 

Wolf, 3, 127; Tasmanian (Thylacine), 119, 141 

Wolverine, 123, 149 

Woodcock, 33, 39, 42, 54, 83, figure 20, p. 33; 
figure 21, p. 33; figure 22, p. 33; figure 
23. P- 33; figure 23, p. 33; figure 80, p. 
82; figure 81, p. 82; figure 82, p. 82 

Wood Creeper. See Creeper 

Wood Duck. See Duck 

Woodpecker, 49, 78, 114, 115, figure 83, p. 114 

Wood Warbler. See Warblers 

Wryneck, 49, 50 



Young animals, patterns of different from 
adults of same species, 60, 80, 82, 83, 
145, 169 



Zebra, 135-140, figure 88, p. 135; figure 89, p. 

136; figure 90, p. 138; figure 91, p. 138; 

and figure 92, p. 138 
Zoril, African, 147, 150 



260